The conversion of CO_(2)into value-added chemicals coupled with the storage of intermittent renewable electricity is attractive.CuO nanosheets with an average size and thickness of~30 and~20 nm have been developed,whi...The conversion of CO_(2)into value-added chemicals coupled with the storage of intermittent renewable electricity is attractive.CuO nanosheets with an average size and thickness of~30 and~20 nm have been developed,which are in situ reduced into Cu nanosheets during electrochemical CO_(2)reduction reaction(ECO_(2)RR).The derived Cu nanosheets demonstrate much higher selectivity for C2H4production than commercial CuO derived Cu powder,with an optimum Faradaic efficiency of 56.2%and a partial current density of C_(2)H_(4)as large as 171.0 mA cm^(-2)in a gas diffusion flow cell.The operando attenuated total reflectance-Fourier transform infrared spectra measurements and density functional theory simulations illustrate that the high activity and selectivity of Cu nanosheets originate from the edge sites on Cu nanosheets with a coordinate number around 5(4–6),which facilitates the formation of^(*)CHO rather than^(*)COH intermediate,meanwhile boosting the C-C coupling reaction of^(*)CO and^(*)CHO intermediates,which are the critical steps for C_(2)H_(4)formation.展开更多
The most challenging goal of C1 chemistry is the control of C–C coupling to produce chemicals or fuels from C1 feedstocks,in particular syngas(H2/CO),which can be derived from various carbon resources such as coal,...The most challenging goal of C1 chemistry is the control of C–C coupling to produce chemicals or fuels from C1 feedstocks,in particular syngas(H2/CO),which can be derived from various carbon resources such as coal,natural gas or shale gas,and biomass.展开更多
Electrocatalytic oxidation reaction of biomass-based derivatives is an excellent candidate to replace water oxidation for obtaining both value-added products and hydrogen(H_(2)),but the exploration of competent electr...Electrocatalytic oxidation reaction of biomass-based derivatives is an excellent candidate to replace water oxidation for obtaining both value-added products and hydrogen(H_(2)),but the exploration of competent electrocatalysts is still highly challenging.Herein,two new types of three-dimensional self-supported hollow microarrays containing CoNi layered double hydroxide(CoNi-LDH)and N-doped carbon nanosheets decorated with CoNi alloyed nanoparticles(CoNi-NC)on carbon cloth(CC)are prepared,which are further used as efficient electrocatalysts for tetrahydroisoquinoline(THIQ)electrooxidation and hydrogen evolution reaction(HER),respectively.We demonstrate that the Co-modulated electronic environment for Ni(II)/Ni(Ⅲ)redox-looping in CoNi-LDH is the main factor to boost the selectivity of 3,4-dihydroisoquinoline(DHIQ)for the indirect electrooxidation process of THIQ.Density functional theory(DFT)calculations reveal that the Ni(Ⅲ)/Co(Ⅲ)dual sites of CoNi-LDH exhibit enhanced adsorption for THIQ but poorer adsorption for DHIQ compared to pure Co(Ⅲ)or Ni(Ⅲ).Therefore,the Ni(Ⅲ)/Co(Ⅲ)dual sites can effectively inhibit the peroxidation of DHIQ to isoquinoline(IQ)over CoNi-LDH,thus improving the selectivity of DHIQ to nearly 100%,much higher than that of its pure Ni counterpart.Moreover,CC@CoNi-NC can deliver high HER activity with low overpotential(40 mV@10 mA·cm^(-2))and high exchange current density(3.08 mA·cm^(-2)).Impressively,the assembled flow-cell device with CC@CoNi-LDH anode and CC@CoNi-NC cathode only requires low cell voltage and electricity consumption of 1.6 V and 3.50 kWh per cubic meter of H_(2)(@25 mA·cm^(-2)).展开更多
Photothermal CO_(2)reduction with H2O,integrating advantages of photocatalysis driven H2O splitting and thermal catalysis promoted CO_(2)reduction,has drawn sharply increasing attention in artificial synthesis of sola...Photothermal CO_(2)reduction with H2O,integrating advantages of photocatalysis driven H2O splitting and thermal catalysis promoted CO_(2)reduction,has drawn sharply increasing attention in artificial synthesis of solar fuels.The photothermal effect of metal nanoparticles facilities CO_(2)hydrogenation and activation of lattice oxygen in oxide photocatalyst promotes H2O oxidation,which is essentially considered for highly efficient photothermal catalysis.However,the large thermal conductivity of most metal nanoparticles induces inevitable heat dissipation,restricting the increase of catalyst temperature.In this work,to minimize the heat dissipation,we employ bismuth nanoparticles as photothermal unit,which is of the lowest thermal conductivity in the metal family.Meanwhile,we adopt bismuth doped NaTaO_(3)as photocatalytic unit because of the bismuth doping induced activation of lattice oxygen.The bismuth nanoparticles are assembled with bismuth doped NaTaO_(3)through one-step tunable transformation from Bi4TaO8Cl.Benefiting from the photothermal effect,thermal insulation caused by bismuth metal,and lattice oxygen activation by bismuth doping,the NaTaO_(3):Bi hybrid exhibits high photothermal catalytic performance.The yield of CO over NaTaO_(3):Bi hybrid at 413 K via photothermal catalysis is 141 times higher than that room temperature photocatalysis.Further,ultraviolet(UV)light irradiation leads to 89.2%selectivity of CO and visible light irradiation leads to 97.5%selectivity of CH4.This work may broaden the photocatalytic application of ABO_(3)perovskite and provides a novel strategy for the development of photothermal catalysts for artificial photosynthesis.展开更多
INTRODUCTION The treatment of small renal masses has shifted from radical nephrectomy to partial nephrectomy, in particular, laparoscopic partial nephrectomy. Renal artery clamping is often necessary to minimize hemor...INTRODUCTION The treatment of small renal masses has shifted from radical nephrectomy to partial nephrectomy, in particular, laparoscopic partial nephrectomy. Renal artery clamping is often necessary to minimize hemorrhage during resection in cases of partial nephrectomy. However, renal artery clamping may lead to greater incidence of renal malfunction after partial nephrectomy. Therefore, novel techniques which could both avoid renal artery occlusion and achieve adequate hemostasis are urgently required. Selective renal segmental artery clamping was one of several common methods that could achieve "zero ischemia." At the same time, a number of reports about laser-assisted partial nephrectomy on humans using multiple kinds of outstanding coagulative specialties of lasers were published.展开更多
A highly selective nitric oxide(NO) sensor is fabricated and applied to devise an enhanced flow injection analysis(FIA) system for S-nitrosothiols(RSNOs) measurement in biological samples.The NO sensor is prepar...A highly selective nitric oxide(NO) sensor is fabricated and applied to devise an enhanced flow injection analysis(FIA) system for S-nitrosothiols(RSNOs) measurement in biological samples.The NO sensor is prepared using a polytetrafluoroethylene(PTFE) gas-permeable membrane loaded with Teflon AF? solution,a copolymer of tetrafluoroethylene and 2,2-bis(trifluoroethylene)-4,5-difluoro -l,3-dioxole,to improve selectivity.This method is much simpler and possesses good performance over a wide range of RSNOs concentrations.Standard deviation for three parallel measurements of blood plasma is 4.0%.The use of the gas sensing configuration as the detector enhances selectivity of the FIA measurement vs.using less selective electrochemical detectors that do not use PTFE/Teflon type outer membranes.展开更多
A new tetraphenylethylene-cyclodextrin (TPE-CD) conjugate with a linkage composed of long triethylene glycol chain and triazole ring on the CD rim has been designed and synthesized. The TPE-CD conjugate exists in a st...A new tetraphenylethylene-cyclodextrin (TPE-CD) conjugate with a linkage composed of long triethylene glycol chain and triazole ring on the CD rim has been designed and synthesized. The TPE-CD conjugate exists in a stretched form in DMSO and enhances its fluorescence after addition of a small amount of water due to aggregation-induced emission (AIE) effect. However, in the presence of a large amount of water, the TPE unit will enter the cyclodextrin cavity to form a folded self-inclusion compound. In the self-inclusion compound, not only nitrogen-containing pseudo-crown ether is formed but also arouses photo-induced electron transfer (PET) process from nitrogen atoms of triazole ring to TPE unit and quenches the fluorescence although more aggregation occurs in more water. This is the first finding that TPE-macrocycle conjugate can form pseudo-crown ether and has both the AIE phenomenon and the PET effect. Interestingly, only mercury ion arouses the fluorescence recover of the self-inclusion compound by entering the pseudo-crown ether cavity and blocking the PET process by binding to the nitrogen atoms, while other tested metal ions almost have no effect on the fluorescence. Therefore, the TPE-CD conjugate can be used for the highly selective fluorescence "Turn-On" detection of Hg^(2+).展开更多
Electrochemical nitric oxide reduction reaction(NORR)to produce ammonia(NH3)under ambient conditions is a promising alternative to the energy and carbon-intensive Haber–Bosch approach,but its performance is still imp...Electrochemical nitric oxide reduction reaction(NORR)to produce ammonia(NH3)under ambient conditions is a promising alternative to the energy and carbon-intensive Haber–Bosch approach,but its performance is still improved.Herein,molybdenum carbides(MoC)nanocrystals confined by nitrogen-doped carbon nanosheets are first designed as an efficient and durable electrocatalyst for catalyzing the reduction of NO to NH3 with maximal Faradaic efficiency of 89%±2%and a yield rate of 1,350±15μg·h^(−1)·cm^(−2) at the applied potential of−0.8 V vs.reversible hydrogen electrode(RHE)as well as high stable activity with negligible current density and NH3 yield rate decays over a 30 h continue the test.Moreover,as a proof-of-concept of Zn–NO battery,it achieves a peak power density of 1.8 mW·cm^(−2) and a large NH3 yield rate of 782±10μg·h^(−1)·cm^(−2),which are comparable to the best-reported results.Theoretical calculations reveal that the MoC(111)has a strong electronic interaction with NO molecules and thus lowering the energy barrier of the potential-determining step and suppressing hydrogen evolution kinetics.This work suggests that Mo-based materials are a powerful platform providing great opportunities to explore highly selective and active catalysts for NH3 production.展开更多
An intramolecularly hydrogen-bonded crescent aromatic oligoamide 1 bearing two coumarin residues was syn- thesized. The results from UV-vis and fluorescent spectra upon metal ions complexation demonstrated that the tw...An intramolecularly hydrogen-bonded crescent aromatic oligoamide 1 bearing two coumarin residues was syn- thesized. The results from UV-vis and fluorescent spectra upon metal ions complexation demonstrated that the two fluorophores serving as parts of the shape-persistent backbone provided the molecule with high selectivity and sen- sitivity for recognition of Th4+ over other lanthanide and uranyl ions. A 48-fold fluorescent enhancement in the in- tensity was observed at 505 nm upon adding Th4+, while other metal cations failed to induce such a significant change. A visual detection for Th4+ was achieved by color change. The stoichiometry of the complex formed by 1 and Th4+ was found to be 1 : 1 with the stability constant of(2.0±0.6) × 10^6 L·mol^-1.展开更多
Conversion of methane into liquid alcohol such as ethanol at low temperature in a straight,selective and low energy consumption process remains a topic of intense scientific research but a great challenge.In this work...Conversion of methane into liquid alcohol such as ethanol at low temperature in a straight,selective and low energy consumption process remains a topic of intense scientific research but a great challenge.In this work,CuFe_(2)O_(4)/CNT composite is successfully synthesized via a facile co-reduction method and used as catalysts to selectively oxidize methane.At a low temperature of 150℃,methane is directly converted to ethanol in a single process on the as-prepared CuFe_(2)O_(4)/CNT composite with high selectivity.A mechanism is also proposed for the significant methane selective oxidation performance of the CuFe_(2)O_(4)/CNT composite catalysts.展开更多
A novel optical chemical sensor L was designed and synthesized for the determination of silver ions.The sensor L was derived from 1-naphthaldehyde and 3,4,5-tris(hexadecyloxy)benzohydrazide.The sensor L shows high sen...A novel optical chemical sensor L was designed and synthesized for the determination of silver ions.The sensor L was derived from 1-naphthaldehyde and 3,4,5-tris(hexadecyloxy)benzohydrazide.The sensor L shows high sensitivity and selectivity for Ag+detection in comparison to other metal cations(Mg^(2+),Ca^(2+),Al^(3+),Cr^(3+),Fe^(3+),Co^(2+),Ni^(2+),Cu^(2+),Zn^(2+),Cd^(2+),Hg^(2+),Pb^(2+))and has no significant response to other common metal cations.Upon addition of Ag+,the fluorescent emission of the sensor L was enhanced dramatically but other metal cations had no same response.The detection limit for Ag+was 1.2×10^(−7) mol/L.Therefore,the sensor L is useful for Ag+detection with some advantages including sensitivity,selectivity,simplicity and low-cost.展开更多
The direct oxidation of nitrogen is a potential pathway to achieving the zero-carbon-emission synthesis of nitric acid or nitrate, because it does not involve ammonia synthesis and additional ammonia oxidation process...The direct oxidation of nitrogen is a potential pathway to achieving the zero-carbon-emission synthesis of nitric acid or nitrate, because it does not involve ammonia synthesis and additional ammonia oxidation processes. However, the slow kinetics of nitrogen oxidation and the difficult selective control of oxidation products hinder the development of this process. In this study, a plasma-driven gas-liquid relay reaction system was developed to overcome these limitations. A typical feature of this reaction system is that it can efficiently generate NO_x under plasma exposure;moreover, the specific anions in the absorption solution can be oxidized to strong oxidants capable of relay oxidation of low-valence nitrogen oxides. This feature allows for the deep oxidation of nitrogen, thus enabling the oxidation products of nitrogen to exist in high-valence states in the absorption solution. For experimental verification, we achieved the 100% selective synthesis of nitrate under plasma exposure, with air as the supply gas and a sodium sulfate solution as the absorption solution.展开更多
Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and c...Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and corrosion.Here,we present a robust and weak-nucleophilicity nickel-iron hydroxide electrocatalyst with excellent selectivity for oxygen evolution and an inert response for chlorine ion oxidation which are key and highly desired for efficient seawater electrolysis.Such a weak-nucleophilicity electrocatalyst can well match with strong-nucleophilicity OH-compared with the weak-nucleophilicity Cl^(-),resultantly,the oxidation of OH-in electrolyte can be more easily achieved relative to chlorine ion oxidation,confirmed by ethylenediaminetetraacetic acid disodium probing test.Further,no strongly corrosive hypochlorite is produced when the operating voltage reaches about 2.1 V vs.RHE,a potential that is far beyond the thermodynamic potential of chlorine ion oxidatio n.This concept and approach to reasonably designing weaknucleophilicity electrocatalysts that can greatly avoid chlorine ion oxidation under alkaline seawater environments can push forward the seawater electrolysis technology and also accelerate the development of green hydrogen technique.展开更多
An inductively coupled plasma (ICP) discharge and its etching behaviors for aluminum alloys were investigated in this report. A radio frequency power supply was used for plasma generation. The unique hardware configur...An inductively coupled plasma (ICP) discharge and its etching behaviors for aluminum alloys were investigated in this report. A radio frequency power supply was used for plasma generation. The unique hardware configuration enabled one to control ion energy separately from plasma density. Plasma properties were measured with a Langmuir probe. Electron temperature, plasma potential and plasma density were found to be comparable with those reported from Electron Cyclotron Resonance (ECR) and other types of reactors[1].A mixture of HBr and chlorine gases were used for this aluminum etch study. Experimental matrices were designed with Response Surface Methodology (RSM) to analyze the process trends versus etch parameters, such as source power, bias power and gas composition. An etch rate of 8500A to 9000A per minute was obtained at 5 to 15 mTorr pressure ranges. Anisotropic profiles with high photoresist selectivity (5 to 1) and silicon dioxide selectivity greater than 10 were achieved with HBr addition into chlorine plasma.Bromine-containing chemistry for an aluminum etch in a low pressure ICP discharge showed great potential for use in ULSI fabrication. In addition, the hardware used was very simple and the chamber size was much smaller than other high density plasma sources.展开更多
Nano Research volume 13,pages1704–1712(2020)Cite this article 191 Accesses Metrics details Abstract Intelligent gas sensors based on the layered transition metal dichalcogenides(TMDs)have attracted great interest in ...Nano Research volume 13,pages1704–1712(2020)Cite this article 191 Accesses Metrics details Abstract Intelligent gas sensors based on the layered transition metal dichalcogenides(TMDs)have attracted great interest in the field of gas sensing due to their multiple active sites,fast electron,mass transfer capability and large surface-to-volume ratio.However,conventional TMDs-based sensors typically work at elevated temperature in inert atmosphere,which would largely limit the corresponding practical applications.Herein,novel oxygen-doped MoSe2 hierarchical nanostructures composed of ultrathin nanosheets with large specific surface area have been designed and generated typically at 200°C in air for fast and facile gas sensing of trimethylamine(TMA),effectively.Benefited from the gas-accessible hierarchical morphology and high surface area with abundant nanochannels,highly sensitive and selective detection of trace TMA has been achieved under ambient condition,and as detected the theoretical limit of detection(LOD)is 8 ppb,which is the lowest for TMA detection under ambient condition among the reported studies.The mechanism of oxygen doping on the improved gas-sensing performance has been investigated,revealing that the oxygen doping could greatly optimize the electronic structure,thus regulate the Fermi level of MoSe2 as well as the affinity between TMA molecule and sensor surface.It is expected that the oxygen doping strategy developed for the highly efficient gas sensors based on TMDs in present work may also be applicable to other types of gas-sensing semiconductors,which could open up a new direction for the rational design of high-performance gas sensors working under ambient condition.展开更多
Ammonia detection possesses great potential in atmosphere environmental protection,agriculture,industry,and rapid medical diagnosis.However,it still remains a great challenge to balance the sensitivity,selectivity,wor...Ammonia detection possesses great potential in atmosphere environmental protection,agriculture,industry,and rapid medical diagnosis.However,it still remains a great challenge to balance the sensitivity,selectivity,working temperature,and response/recovery speed.In this work,Berlin green(BG)framework is demonstrated as a highly promising sensing material for ammonia detection by both density functional theory simulation and experimental gas sensing investigation.Vacancy in BG framework offers abundant active sites for ammonia absorption,and the absorbed ammonia transfers sufficient electron to BG,arousing remarkable enhancement of resistance.Pristine BG framework shows remarkable response to ammonia at 50–110°C with the highest response at 80°C,which is jointly influenced by ammonia’s absorption onto BG surface and insertion into BG lattice.The sensing performance of BG can hardly be achieved at room temperature due to its high resistance.Introduction of conductive Ti3CN MXene overcomes the high resistance of pure BG framework,and the simply prepared BG/Ti3CN mixture shows high selectivity to ammonia at room temperature with satisfying response/recovery speed.展开更多
The electrochemical nitrogen reduction reaction(NRR)to directly produce NH3 from N_(2) and H_(2)O under ambient conditions has attracted significant attention due to its ecofriendliness.Nevertheless,the electrochemica...The electrochemical nitrogen reduction reaction(NRR)to directly produce NH3 from N_(2) and H_(2)O under ambient conditions has attracted significant attention due to its ecofriendliness.Nevertheless,the electrochemical NRR presents several practical challenges,including sluggish reaction and low selectivity.Here,bi-atom catalysts have been proposed to achieve excellent activity and high selectivity toward the electrochemical NRR by Ma and his co-workers.It could accelerate the kinetics of N_(2)-to-NH_(3) electrochemical conversion and possess better electrochemical NRR selectivity.This work sheds light on the introduction of bi-atom catalysts to enhance the performance of the electrochemical NRR.展开更多
People living on the high plateaus of the world have long fascinated biological anthropologists and geneticists because they live in "thin air" and epitomize an extreme of human biological adaptation.
La_(2)O_(3) catalyzed oxidative coupling of methane(OCM) is a promising process that converts methane directly to valuable C_(2)(ethylene and ethane) products. Our online MS transient study results indicate that prist...La_(2)O_(3) catalyzed oxidative coupling of methane(OCM) is a promising process that converts methane directly to valuable C_(2)(ethylene and ethane) products. Our online MS transient study results indicate that pristine surface without carbonate species demonstrates a higher selectivity to C_(2) products, and a lower light-off temperature as well. Further study is focused on carbonate-free La_(2)O_(3) catalyst surface for identification of active oxygen species associated with such products behavior. XPS reveals unique oxygen species with O 1 s binding energy of 531.5 e V correlated with OCM catalytic activity and carbonates removal. However, indicated thermal stability of this species is much higher than the surface peroxide or superoxide structures proposed by earlier computation models. Motivated by experimental results,DFT calculations reveal a new more stable peroxide structure, formed at the subsurface hexacoordinate lattice oxygen sites, with energy 2.18 e V lower than the previous models. The new model of subsurface peroxide provides a perspective for understanding of methyl radicals formation and C_(2) products selectivity in OCM over La_(2)O_(3) catalyst.展开更多
Photodeposition is widely adopted for implanting metal/metal oxide cocatalysts on semiconductors.However,it is prerequisite that the photon energy should be sufficient to excite the host semiconductor.Here,we report a...Photodeposition is widely adopted for implanting metal/metal oxide cocatalysts on semiconductors.However,it is prerequisite that the photon energy should be sufficient to excite the host semiconductor.Here,we report a lower-energy irradiation powered deposition strategy for implanting CrO_(x) cocatalyst on TiO_(2).Excitingly,CrO_(x)-400 implanted under visible-light irradiation significantly promotes the CH4 evolution rate on TiO_(2)to 8.4μmolg·^(-1)h^(-1) with selectivity of98%from photocatalytic CO_(2)reduction,which is 15 times of that on CrO_(x)-200 implanted under UV-visible-light irradiation.Moreover,CrO_(x)-400 is identified to be composed of higher valence Cr species compared to CrO_(x)-200.This valence states regulation of Cr species is indicated to provide more active sites for CO_(2) adsorption/activation and to modulate the reaction mechanism from single Cr site to Cr-Cr dual sites,thus endowing the superior CH_(4)production.This work demonstrates an alternative strategy for constructing efficient metal oxides cocatalysts on wide bandgap semiconductor.展开更多
基金funded by the National Key Research and Development Program of China(2017YFA0700103,2018YFA0704502)the National Natural Science Foundation of China(21703248)staffs in BL11B beamline in Shanghai Synchrotron Radiation Facility(SSRF)for their technical assistance(2020-SSRF-PT-012223 and 2021-SSRF-PT-015319)。
文摘The conversion of CO_(2)into value-added chemicals coupled with the storage of intermittent renewable electricity is attractive.CuO nanosheets with an average size and thickness of~30 and~20 nm have been developed,which are in situ reduced into Cu nanosheets during electrochemical CO_(2)reduction reaction(ECO_(2)RR).The derived Cu nanosheets demonstrate much higher selectivity for C2H4production than commercial CuO derived Cu powder,with an optimum Faradaic efficiency of 56.2%and a partial current density of C_(2)H_(4)as large as 171.0 mA cm^(-2)in a gas diffusion flow cell.The operando attenuated total reflectance-Fourier transform infrared spectra measurements and density functional theory simulations illustrate that the high activity and selectivity of Cu nanosheets originate from the edge sites on Cu nanosheets with a coordinate number around 5(4–6),which facilitates the formation of^(*)CHO rather than^(*)COH intermediate,meanwhile boosting the C-C coupling reaction of^(*)CO and^(*)CHO intermediates,which are the critical steps for C_(2)H_(4)formation.
文摘The most challenging goal of C1 chemistry is the control of C–C coupling to produce chemicals or fuels from C1 feedstocks,in particular syngas(H2/CO),which can be derived from various carbon resources such as coal,natural gas or shale gas,and biomass.
基金support from the Natural Science Foundation of Guangdong Province(No.2023B1515040005)the National Natural Science Foundation of China(Nos.22378135,21825802,and 22138003)the State Key Laboratory of Pulp and Paper Engineering(No.2022PY05).
文摘Electrocatalytic oxidation reaction of biomass-based derivatives is an excellent candidate to replace water oxidation for obtaining both value-added products and hydrogen(H_(2)),but the exploration of competent electrocatalysts is still highly challenging.Herein,two new types of three-dimensional self-supported hollow microarrays containing CoNi layered double hydroxide(CoNi-LDH)and N-doped carbon nanosheets decorated with CoNi alloyed nanoparticles(CoNi-NC)on carbon cloth(CC)are prepared,which are further used as efficient electrocatalysts for tetrahydroisoquinoline(THIQ)electrooxidation and hydrogen evolution reaction(HER),respectively.We demonstrate that the Co-modulated electronic environment for Ni(II)/Ni(Ⅲ)redox-looping in CoNi-LDH is the main factor to boost the selectivity of 3,4-dihydroisoquinoline(DHIQ)for the indirect electrooxidation process of THIQ.Density functional theory(DFT)calculations reveal that the Ni(Ⅲ)/Co(Ⅲ)dual sites of CoNi-LDH exhibit enhanced adsorption for THIQ but poorer adsorption for DHIQ compared to pure Co(Ⅲ)or Ni(Ⅲ).Therefore,the Ni(Ⅲ)/Co(Ⅲ)dual sites can effectively inhibit the peroxidation of DHIQ to isoquinoline(IQ)over CoNi-LDH,thus improving the selectivity of DHIQ to nearly 100%,much higher than that of its pure Ni counterpart.Moreover,CC@CoNi-NC can deliver high HER activity with low overpotential(40 mV@10 mA·cm^(-2))and high exchange current density(3.08 mA·cm^(-2)).Impressively,the assembled flow-cell device with CC@CoNi-LDH anode and CC@CoNi-NC cathode only requires low cell voltage and electricity consumption of 1.6 V and 3.50 kWh per cubic meter of H_(2)(@25 mA·cm^(-2)).
基金supported by the Natural Science Foundation of China(Nos.91833303,52273236,and 51872044)the 111 Project(No.B13013)Jilin Province Science and Technology Development Project(No.20220201073GX).
文摘Photothermal CO_(2)reduction with H2O,integrating advantages of photocatalysis driven H2O splitting and thermal catalysis promoted CO_(2)reduction,has drawn sharply increasing attention in artificial synthesis of solar fuels.The photothermal effect of metal nanoparticles facilities CO_(2)hydrogenation and activation of lattice oxygen in oxide photocatalyst promotes H2O oxidation,which is essentially considered for highly efficient photothermal catalysis.However,the large thermal conductivity of most metal nanoparticles induces inevitable heat dissipation,restricting the increase of catalyst temperature.In this work,to minimize the heat dissipation,we employ bismuth nanoparticles as photothermal unit,which is of the lowest thermal conductivity in the metal family.Meanwhile,we adopt bismuth doped NaTaO_(3)as photocatalytic unit because of the bismuth doping induced activation of lattice oxygen.The bismuth nanoparticles are assembled with bismuth doped NaTaO_(3)through one-step tunable transformation from Bi4TaO8Cl.Benefiting from the photothermal effect,thermal insulation caused by bismuth metal,and lattice oxygen activation by bismuth doping,the NaTaO_(3):Bi hybrid exhibits high photothermal catalytic performance.The yield of CO over NaTaO_(3):Bi hybrid at 413 K via photothermal catalysis is 141 times higher than that room temperature photocatalysis.Further,ultraviolet(UV)light irradiation leads to 89.2%selectivity of CO and visible light irradiation leads to 97.5%selectivity of CH4.This work may broaden the photocatalytic application of ABO_(3)perovskite and provides a novel strategy for the development of photothermal catalysts for artificial photosynthesis.
文摘INTRODUCTION The treatment of small renal masses has shifted from radical nephrectomy to partial nephrectomy, in particular, laparoscopic partial nephrectomy. Renal artery clamping is often necessary to minimize hemorrhage during resection in cases of partial nephrectomy. However, renal artery clamping may lead to greater incidence of renal malfunction after partial nephrectomy. Therefore, novel techniques which could both avoid renal artery occlusion and achieve adequate hemostasis are urgently required. Selective renal segmental artery clamping was one of several common methods that could achieve "zero ischemia." At the same time, a number of reports about laser-assisted partial nephrectomy on humans using multiple kinds of outstanding coagulative specialties of lasers were published.
基金the Project of Base for Introducing Talents of Discipline to Universities(111 project,NoB07012)National Scholarship Fund of the China Scholarship Council for supporting visiting students in foreign universities
文摘A highly selective nitric oxide(NO) sensor is fabricated and applied to devise an enhanced flow injection analysis(FIA) system for S-nitrosothiols(RSNOs) measurement in biological samples.The NO sensor is prepared using a polytetrafluoroethylene(PTFE) gas-permeable membrane loaded with Teflon AF? solution,a copolymer of tetrafluoroethylene and 2,2-bis(trifluoroethylene)-4,5-difluoro -l,3-dioxole,to improve selectivity.This method is much simpler and possesses good performance over a wide range of RSNOs concentrations.Standard deviation for three parallel measurements of blood plasma is 4.0%.The use of the gas sensing configuration as the detector enhances selectivity of the FIA measurement vs.using less selective electrochemical detectors that do not use PTFE/Teflon type outer membranes.
基金National Natural Science Foundation of China(Nos. 91856125 and 21673089)HUST Graduate Innovation Fund for financial support。
文摘A new tetraphenylethylene-cyclodextrin (TPE-CD) conjugate with a linkage composed of long triethylene glycol chain and triazole ring on the CD rim has been designed and synthesized. The TPE-CD conjugate exists in a stretched form in DMSO and enhances its fluorescence after addition of a small amount of water due to aggregation-induced emission (AIE) effect. However, in the presence of a large amount of water, the TPE unit will enter the cyclodextrin cavity to form a folded self-inclusion compound. In the self-inclusion compound, not only nitrogen-containing pseudo-crown ether is formed but also arouses photo-induced electron transfer (PET) process from nitrogen atoms of triazole ring to TPE unit and quenches the fluorescence although more aggregation occurs in more water. This is the first finding that TPE-macrocycle conjugate can form pseudo-crown ether and has both the AIE phenomenon and the PET effect. Interestingly, only mercury ion arouses the fluorescence recover of the self-inclusion compound by entering the pseudo-crown ether cavity and blocking the PET process by binding to the nitrogen atoms, while other tested metal ions almost have no effect on the fluorescence. Therefore, the TPE-CD conjugate can be used for the highly selective fluorescence "Turn-On" detection of Hg^(2+).
基金supported by National Natural Science Foundation of China(Nos.22075211,22109118,21601136,51971157,and 51621003).
文摘Electrochemical nitric oxide reduction reaction(NORR)to produce ammonia(NH3)under ambient conditions is a promising alternative to the energy and carbon-intensive Haber–Bosch approach,but its performance is still improved.Herein,molybdenum carbides(MoC)nanocrystals confined by nitrogen-doped carbon nanosheets are first designed as an efficient and durable electrocatalyst for catalyzing the reduction of NO to NH3 with maximal Faradaic efficiency of 89%±2%and a yield rate of 1,350±15μg·h^(−1)·cm^(−2) at the applied potential of−0.8 V vs.reversible hydrogen electrode(RHE)as well as high stable activity with negligible current density and NH3 yield rate decays over a 30 h continue the test.Moreover,as a proof-of-concept of Zn–NO battery,it achieves a peak power density of 1.8 mW·cm^(−2) and a large NH3 yield rate of 782±10μg·h^(−1)·cm^(−2),which are comparable to the best-reported results.Theoretical calculations reveal that the MoC(111)has a strong electronic interaction with NO molecules and thus lowering the energy barrier of the potential-determining step and suppressing hydrogen evolution kinetics.This work suggests that Mo-based materials are a powerful platform providing great opportunities to explore highly selective and active catalysts for NH3 production.
基金the National Natural Science Foundation of China,NSAF,Sichuan Province Science and Technology Support Programme,the National Fund of China for Fostering Talents in Basic Science,the Open Project of Key Laboratory for Radiation Physics and Technology of Ministry of Education (2010-08).Analytical & Testing Center of Sichuan University is acknowledged for NMR analyses
文摘An intramolecularly hydrogen-bonded crescent aromatic oligoamide 1 bearing two coumarin residues was syn- thesized. The results from UV-vis and fluorescent spectra upon metal ions complexation demonstrated that the two fluorophores serving as parts of the shape-persistent backbone provided the molecule with high selectivity and sen- sitivity for recognition of Th4+ over other lanthanide and uranyl ions. A 48-fold fluorescent enhancement in the in- tensity was observed at 505 nm upon adding Th4+, while other metal cations failed to induce such a significant change. A visual detection for Th4+ was achieved by color change. The stoichiometry of the complex formed by 1 and Th4+ was found to be 1 : 1 with the stability constant of(2.0±0.6) × 10^6 L·mol^-1.
基金financially supported by the National Natural Science Foundation of China(No.21975163)Bureau of Industry and Information Technology of Shenzhen(No.201901171518)+1 种基金Shenzhen Science and Technology Program(No.KQTD20190929173914967)the support provided by Instrumental Analysis Center of Shenzhen University(Xili Campus)。
文摘Conversion of methane into liquid alcohol such as ethanol at low temperature in a straight,selective and low energy consumption process remains a topic of intense scientific research but a great challenge.In this work,CuFe_(2)O_(4)/CNT composite is successfully synthesized via a facile co-reduction method and used as catalysts to selectively oxidize methane.At a low temperature of 150℃,methane is directly converted to ethanol in a single process on the as-prepared CuFe_(2)O_(4)/CNT composite with high selectivity.A mechanism is also proposed for the significant methane selective oxidation performance of the CuFe_(2)O_(4)/CNT composite catalysts.
基金This work was supported by the National Natural Science Foundation of China(Nos.21064006,21262032 and 21161018)the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT1177)+2 种基金the Natural Science Foundation of Gansu Province(No.1010RJZA018)the Youth Foundation of Gansu Province(No.2011GS04735)NWNU-LKQN-11-32.
文摘A novel optical chemical sensor L was designed and synthesized for the determination of silver ions.The sensor L was derived from 1-naphthaldehyde and 3,4,5-tris(hexadecyloxy)benzohydrazide.The sensor L shows high sensitivity and selectivity for Ag+detection in comparison to other metal cations(Mg^(2+),Ca^(2+),Al^(3+),Cr^(3+),Fe^(3+),Co^(2+),Ni^(2+),Cu^(2+),Zn^(2+),Cd^(2+),Hg^(2+),Pb^(2+))and has no significant response to other common metal cations.Upon addition of Ag+,the fluorescent emission of the sensor L was enhanced dramatically but other metal cations had no same response.The detection limit for Ag+was 1.2×10^(−7) mol/L.Therefore,the sensor L is useful for Ag+detection with some advantages including sensitivity,selectivity,simplicity and low-cost.
基金supported by the National Key R&D Program of China (2021YFB4000402)the National Natural Science Foundation of China (22022503)。
文摘The direct oxidation of nitrogen is a potential pathway to achieving the zero-carbon-emission synthesis of nitric acid or nitrate, because it does not involve ammonia synthesis and additional ammonia oxidation processes. However, the slow kinetics of nitrogen oxidation and the difficult selective control of oxidation products hinder the development of this process. In this study, a plasma-driven gas-liquid relay reaction system was developed to overcome these limitations. A typical feature of this reaction system is that it can efficiently generate NO_x under plasma exposure;moreover, the specific anions in the absorption solution can be oxidized to strong oxidants capable of relay oxidation of low-valence nitrogen oxides. This feature allows for the deep oxidation of nitrogen, thus enabling the oxidation products of nitrogen to exist in high-valence states in the absorption solution. For experimental verification, we achieved the 100% selective synthesis of nitrate under plasma exposure, with air as the supply gas and a sodium sulfate solution as the absorption solution.
基金supported by the National Natural Science Foundation of China(NSFC,No.22078052)the Fundamental Research Funds for the Central Universities(DUT22ZD207,DUT22LAB612)。
文摘Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and corrosion.Here,we present a robust and weak-nucleophilicity nickel-iron hydroxide electrocatalyst with excellent selectivity for oxygen evolution and an inert response for chlorine ion oxidation which are key and highly desired for efficient seawater electrolysis.Such a weak-nucleophilicity electrocatalyst can well match with strong-nucleophilicity OH-compared with the weak-nucleophilicity Cl^(-),resultantly,the oxidation of OH-in electrolyte can be more easily achieved relative to chlorine ion oxidation,confirmed by ethylenediaminetetraacetic acid disodium probing test.Further,no strongly corrosive hypochlorite is produced when the operating voltage reaches about 2.1 V vs.RHE,a potential that is far beyond the thermodynamic potential of chlorine ion oxidatio n.This concept and approach to reasonably designing weaknucleophilicity electrocatalysts that can greatly avoid chlorine ion oxidation under alkaline seawater environments can push forward the seawater electrolysis technology and also accelerate the development of green hydrogen technique.
文摘An inductively coupled plasma (ICP) discharge and its etching behaviors for aluminum alloys were investigated in this report. A radio frequency power supply was used for plasma generation. The unique hardware configuration enabled one to control ion energy separately from plasma density. Plasma properties were measured with a Langmuir probe. Electron temperature, plasma potential and plasma density were found to be comparable with those reported from Electron Cyclotron Resonance (ECR) and other types of reactors[1].A mixture of HBr and chlorine gases were used for this aluminum etch study. Experimental matrices were designed with Response Surface Methodology (RSM) to analyze the process trends versus etch parameters, such as source power, bias power and gas composition. An etch rate of 8500A to 9000A per minute was obtained at 5 to 15 mTorr pressure ranges. Anisotropic profiles with high photoresist selectivity (5 to 1) and silicon dioxide selectivity greater than 10 were achieved with HBr addition into chlorine plasma.Bromine-containing chemistry for an aluminum etch in a low pressure ICP discharge showed great potential for use in ULSI fabrication. In addition, the hardware used was very simple and the chamber size was much smaller than other high density plasma sources.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.U1932150 and 21571166)Anhui Provincial Natural Science Foundation(No.1908085QB72)the Fundamental Research Funds for the Central Universities(No.WK2060190099).
文摘Nano Research volume 13,pages1704–1712(2020)Cite this article 191 Accesses Metrics details Abstract Intelligent gas sensors based on the layered transition metal dichalcogenides(TMDs)have attracted great interest in the field of gas sensing due to their multiple active sites,fast electron,mass transfer capability and large surface-to-volume ratio.However,conventional TMDs-based sensors typically work at elevated temperature in inert atmosphere,which would largely limit the corresponding practical applications.Herein,novel oxygen-doped MoSe2 hierarchical nanostructures composed of ultrathin nanosheets with large specific surface area have been designed and generated typically at 200°C in air for fast and facile gas sensing of trimethylamine(TMA),effectively.Benefited from the gas-accessible hierarchical morphology and high surface area with abundant nanochannels,highly sensitive and selective detection of trace TMA has been achieved under ambient condition,and as detected the theoretical limit of detection(LOD)is 8 ppb,which is the lowest for TMA detection under ambient condition among the reported studies.The mechanism of oxygen doping on the improved gas-sensing performance has been investigated,revealing that the oxygen doping could greatly optimize the electronic structure,thus regulate the Fermi level of MoSe2 as well as the affinity between TMA molecule and sensor surface.It is expected that the oxygen doping strategy developed for the highly efficient gas sensors based on TMDs in present work may also be applicable to other types of gas-sensing semiconductors,which could open up a new direction for the rational design of high-performance gas sensors working under ambient condition.
基金The research was supported by the National Natural Science Foundation of China(Grant Nos.61435010,61675135,and 62005177)the National Natural Science Foundation for Young Scientists of China(Grant No.61905161)the Science and Technology Innovation Commission of Shenzhen(JCYJ20190808142415003).Authors also acknowledge the support from Instrumental Analysis Center of Shenzhen University(Xili Campus).
文摘Ammonia detection possesses great potential in atmosphere environmental protection,agriculture,industry,and rapid medical diagnosis.However,it still remains a great challenge to balance the sensitivity,selectivity,working temperature,and response/recovery speed.In this work,Berlin green(BG)framework is demonstrated as a highly promising sensing material for ammonia detection by both density functional theory simulation and experimental gas sensing investigation.Vacancy in BG framework offers abundant active sites for ammonia absorption,and the absorbed ammonia transfers sufficient electron to BG,arousing remarkable enhancement of resistance.Pristine BG framework shows remarkable response to ammonia at 50–110°C with the highest response at 80°C,which is jointly influenced by ammonia’s absorption onto BG surface and insertion into BG lattice.The sensing performance of BG can hardly be achieved at room temperature due to its high resistance.Introduction of conductive Ti3CN MXene overcomes the high resistance of pure BG framework,and the simply prepared BG/Ti3CN mixture shows high selectivity to ammonia at room temperature with satisfying response/recovery speed.
文摘The electrochemical nitrogen reduction reaction(NRR)to directly produce NH3 from N_(2) and H_(2)O under ambient conditions has attracted significant attention due to its ecofriendliness.Nevertheless,the electrochemical NRR presents several practical challenges,including sluggish reaction and low selectivity.Here,bi-atom catalysts have been proposed to achieve excellent activity and high selectivity toward the electrochemical NRR by Ma and his co-workers.It could accelerate the kinetics of N_(2)-to-NH_(3) electrochemical conversion and possess better electrochemical NRR selectivity.This work sheds light on the introduction of bi-atom catalysts to enhance the performance of the electrochemical NRR.
文摘People living on the high plateaus of the world have long fascinated biological anthropologists and geneticists because they live in "thin air" and epitomize an extreme of human biological adaptation.
基金the Key Projects of Shanghai Science and Technology Commission (18JC1412100)the National Natural Science Foundation of China (No. 91745105, 22072092, 92045301)+2 种基金the startup funding provided by Shanghai Tech University for funding their participation in this workfunding provided through The Shell Foundation Grants (No. PT66201)the support from Analytical Instrumentation Center (contract no. SPSTAIC10112914), SPST, Shanghai Tech University。
文摘La_(2)O_(3) catalyzed oxidative coupling of methane(OCM) is a promising process that converts methane directly to valuable C_(2)(ethylene and ethane) products. Our online MS transient study results indicate that pristine surface without carbonate species demonstrates a higher selectivity to C_(2) products, and a lower light-off temperature as well. Further study is focused on carbonate-free La_(2)O_(3) catalyst surface for identification of active oxygen species associated with such products behavior. XPS reveals unique oxygen species with O 1 s binding energy of 531.5 e V correlated with OCM catalytic activity and carbonates removal. However, indicated thermal stability of this species is much higher than the surface peroxide or superoxide structures proposed by earlier computation models. Motivated by experimental results,DFT calculations reveal a new more stable peroxide structure, formed at the subsurface hexacoordinate lattice oxygen sites, with energy 2.18 e V lower than the previous models. The new model of subsurface peroxide provides a perspective for understanding of methyl radicals formation and C_(2) products selectivity in OCM over La_(2)O_(3) catalyst.
基金supported by the National Key Research and Development Program of China(2016YFB0700205,2017YFA0403402,2019YFA0405602,2017YFA0204904)the National Natural Science Foundation of China(52002367,21673214,U1732272,U1632273,U1832165)+1 种基金the foundation from Users with Excellence Program of Hefei Science Center CAS(2020HSC-UE001)the Fundamental Research Funds for the Central Universities(WK2310000093)。
文摘Photodeposition is widely adopted for implanting metal/metal oxide cocatalysts on semiconductors.However,it is prerequisite that the photon energy should be sufficient to excite the host semiconductor.Here,we report a lower-energy irradiation powered deposition strategy for implanting CrO_(x) cocatalyst on TiO_(2).Excitingly,CrO_(x)-400 implanted under visible-light irradiation significantly promotes the CH4 evolution rate on TiO_(2)to 8.4μmolg·^(-1)h^(-1) with selectivity of98%from photocatalytic CO_(2)reduction,which is 15 times of that on CrO_(x)-200 implanted under UV-visible-light irradiation.Moreover,CrO_(x)-400 is identified to be composed of higher valence Cr species compared to CrO_(x)-200.This valence states regulation of Cr species is indicated to provide more active sites for CO_(2) adsorption/activation and to modulate the reaction mechanism from single Cr site to Cr-Cr dual sites,thus endowing the superior CH_(4)production.This work demonstrates an alternative strategy for constructing efficient metal oxides cocatalysts on wide bandgap semiconductor.