Visible Light-Induced Photocatalysis:Self-Fenton Degradation of p-CIPhOH Over Graphitic Carbon Nitride by a Polyethylenimine Bifunctional Catalyst

Deep degradation of organic pollutants by sunlight-induced coupled photocatalytic and Fenton (photo-Fenton) reactions is of immense importance for water purification. In this work, we report a novel bifunctional catalyst (Fe-PEI-CN) by codoping graphitic carbon nitride (CN) with polyethyleneimine ethoxylated (PEI) and Fe species, which demonstrated high activity during p-chlorophenol (p-ClPhOH) degradation via H_(2)O_(2) from the photocatalytic process. The relationship between the catalytic efficiency and the structure was explored using diff erent characterization methods. The Fe modification of CN was achieved through Fe-N coordination, which ensured high dispersion of Fe species and strong stability against leaching during liquid- phase reactions. The Fe modification initiated the Fenton reaction by activating H_(2)O_(2) into ·OH radicals for deep degradation of p-ClPhOH. In addition, it eff ectively promoted light absorption and photoelectron-hole (e-h ^(+) ) separation, corresponding to improved photocatalytic activity. On the other hand, PEI could significantly improve the ability of CN to generate H_(2)O_(2) through visible light photocatalysis. The maximum H_(2)O_(2) yield reached up to 102.6 μmol/L, which was 22 times higher than that of primitive CN. The cooperation of photocatalysis and the self-Fenton reaction has led to high-activity mineralizing organic pollutants with strong durability, indicating good potential for practical application in wastewater treatment.

Radiation-induced cross-linking:a novel avenue to permanent 3D modification of polymeric membranes

Membrane fouling is always the biggest problem in the practice of membrane separation technologies,which strongly impacts their applicability,separation efficiency,cost effectiveness,and service lifespan.Herein,a simple but effective 3D modification approach was designed for permanently functionalizing polymeric membranes by directly cross-linking polyvinyl alcohol(PVA)under gamma-ray irradiation at room temperature without any additives.After the modification,a PVA layer was constructed on the membrane surface and the pore inner surface of polyvinylidene fluoride(PVDF)membranes.This endowed them with good hydrophilicity,low adsorption of protein model foulants,and easy recoverability properties.In addition,the pore size and distribution were customized by controlling the PVA concentration,which enhanced the rejection ability of the resultant membranes and converted them from microfiltration to ultrafiltration.The crosslinked PVA layer was equipped with the resultant membranes with good resistance to chemical cleaning by acidic,alkaline,and oxidative reagents,which could greatly prolong the membrane service lifetime.Furthermore,this approach was demonstrated as a universal method to modify PVDF membranes with other hydrophilic macromolecular modifiers,including polyethylene glycol,sodium alginate,and polyvinyl pyrrolidone.This modification of the membranes effectively endowed them with good hydrophilicity and antifouling properties,as expected.

Enhancing Photocatalytic Performance of NH 2-UIO66 by Defective Structural Engineering

NH_(2)-UIO66(NU)is a promising photocatalyst for the reduction of Cr(VI)to low-toxic Cr(III)driven by visible light under ambient conditions.However,the main limitation in this process is the ineffi cient ligand to metal charge transfer(LMCT)of photo-excited electrons,which is caused by inherent energy gap(ΔE_(LMCT)).This study synthesized the defective NU(NUXH,where X is the molar equivalent of the modulator)with reducedΔE_(LMCT)through linkers removal via acid treatment.The electronic structure of NUX-H was systematically investigated,and the results indicated that the structural defects in NUX-H strongly altered the environment of the Zr atoms.Furthermore,they substantially lowered the energy of the unoccupied d orbitals(LUMO),which was benefi cial to effi cient LMCT,resulting in an improved photocatalytic activity of NUX-H toward high-concentration(100 mg/L)Cr(VI)reduction.Compared to NU with defect-free structure,the reducing rate of Cr(VI)was increased by 47 times.This work introduced an alternative strategy in terms of designing effi cient photocatalysts for reducing Cr(VI)under ambient conditions.

The self-assembly of gold nanoparticles in large-pore ordered mesoporous carbons

Simple encapsulation of 3 nm gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal–ligand coordination assisted-selfassembly approach.Polystyrene-block-polyethylene-oxide(PS-b-PEO)diblock copolymer with a large molecular weight of the PS chain and mercaptopropyltrimethoxysilane were used as the template and the metal ligand,respectively.Small-angle X-ray scattering,X-ray diffraction,transmission electron microscopy,and X-ray photoelectron spectroscopy showed that monodispersed aggregation-free gold nanoparticles approximately 3 nm in size were partially embedded in the large open pore structure of the ordered mesoporous carbon.The strong coordination between the gold species and the mercapto groups and the thick porous walls increased the dispersion of the gold nanoparticles and essentially inhibited particle aggregation at 600℃.The gold nanoparticles in the ordered mesoporous carbon are active and stable in the reduction of nitroarenes involving bulky molecules using sodium borohydride as a reducing agent under ambient conditions(30℃)in water.The large interconnected pore structure facilitates the mass transfer of bulky molecules.

Research Progress on Photocatalytic/Photoelectrocatalytic Oxidation of Nitrogen Oxides

The emission of nitrogen oxides(NO_(x))increases year by year,causing serious problems to our livelihoods.The photocatalytic oxidation of NO_(x)has attracted more attention recently because of its effi cient removal of NO_(x),especially for low concentra-tions of NO_(x).In this review,the mechanism of the photocatalytic oxidation of NO_(x)is described.Then,the recent progress on the development of photocatalysts is reviewed according to the categories of inorganic semiconductors,bismuth-based compounds,nitrogen carbide polymer,and metal organic frameworks(MOFs).In addition,the photoelectrocatalytic oxida-tion of NO_(x),a method involving the application of an external voltage on the photocatalytic system to further increase the removal effi ciency of NO_(x),and its progress are summarized.Finally,we outline the remaining challenges and provide our perspectives on the future directions for the photocatalytic oxidation of NO_(x).

Magnetic Fe_3O_4-Reduced Graphene Oxide Nanocomposites-Based Electrochemical Biosensing

An electrochemical biosensing platform was developed based on glucose oxidase(GOx)/Fe3O4-reduced graphene oxide(Fe3O4-RGO) nanosheets loaded on the magnetic glassy carbon electrode(MGCE).With the advantages of the magnetism, conductivity and biocompatibility of the Fe3O4-RGO nanosheets, the nanocomposites could be facilely adhered to the electrode surface by magnetically controllable assembling and beneficial to achieve the direct redox reactions and electrocatalytic behaviors of GOx immobilized into the nanocomposites. The biosensor exhibited good electrocatalytic activity, high sensitivity and stability. The current response is linear over glucose concentration ranging from 0.05 to 1.5 m M with a low detection limit of0.15 μM. Meanwhile, validation of the applicability of the biosensor was carried out by determining glucose in serum samples. The proposed protocol is simple, inexpensive and convenient, which shows great potential in biosensing application.

A highly selective magnetic sensor with functionalized Fe/Fe_3O_4 nanoparticles for detection of Pb^(2+)

A magnetic sensor for detection of Pb^2＋ has been developed based on Fe/Fe3O4 nanoparticles modified by3-（3,4-dihydroxyphenyl）propionic acid（DHCA）. The carboxyl groups of DHCA have a strong affinity to coordination behavior of Pb^2＋ thus inducing the transformation of Fe/Fe3O4 nanoparticles from a dispersed to an aggregated state with a corresponding decrease, then increase in transverse relaxation time（T2） of the surrounding water protons. Upon addition of the different concentrations of Pb^2＋ to an aq. solution of DHCA functionalized Fe/Fe3O4 nanoparticles（DHCA-Fe/Fe3O4 NPs）（[Fe] = 90 mmol/L）, the change of T2 values display a good linear relationship with the concentration of Pb^2＋ from 40 μmol/L to 100 μmol/L and from 130 μmol/L to 200 μmol/L, respectively. Owing to the especially strong interaction between DHCA and Pb^2＋, DHCA-Fe/Fe3O4 NPs exhibited a high selectivity over other metal ions.

新型多孔催化材料专栏前言（英文）

Over the last 15-20 years a wide range of new porous catalytic materials has been discovered in the wake of major developments in mesostructured materials and hybrid porous solids such as metal organic frameworks(MOFs).These two developments have both enormous potential to produce catalyst supports and solids.It may be argued that most existing industrial catalysts may be revisited for improvement taking advantage of the novel materials.In both cases new

Engineering Pt heterogeneous catalysts for accelerated liquid–solid redox conversion in Li-S batteries

The shuttle effect caused by soluble lithium polysulfides (LiPSs) deteriorates multiphase transformation reaction kinetics of sulfur species,and gives rise to an unserviceable lithium-sulfur (Li-S) battery.Catalysis,as a process optimization approach,offers an option to eliminate the intrinsic issues.However,exploring and understanding the role of catalysts on electrode reaction remains critical bottlenecks,particularly as they are prone to continuous evolution under complex dynamic environment.Herein,platinum nanoparticles loaded on MXene nanosheets,as sulfur host,and the action of catalysts on the reaction process are investigated via ex-situ monitors upon solid–liquid–solid chemical transformation of sulfur species.These traces confirm that the high performance originates from electron transfer between catalysts and LiPSs,which lowers the nucleation barrier from liquid LiPSs to solid Li_(2)S/Li_(2)S_(2).Further,the accelerated liquid–solid conversion can alleviate the accumulation of LiPSs,and boost the reaction kinetics in Li-S batteries.The findings corroborate the electronic modulation between catalysts and LiPSs,which is a generalizable strategy to optimize energy conversion efficiency of Li-S batteries.

Preparation and synergetic catalytic effects of amino-functionalized MCM-41 catalysts

Four amine functionalized mesoporous catalysts were synthesized by grafting primary, dualistic and two secondary amines onto the channel walls of mesoporous silica, MCM-41. We examined the effects of organoamine loading amount on the acid-base synergism of the catalysts in the self-condensation reaction of n-butanal, a Knoevenagel condensation and a Henry reaction. We observed the balance of the amine and residual silanol amounts is crucial to the catalytic performances of the functionalized mesoporous catalysts. An optimum organoamine loading amount exists, which is dependent on the organoamine type. There is little difference in the optimum organoamine loading amount between different reactions. The secondary organoamine functionalized MCM-41 exhibits the best catalytic performance in the experimental range.

Barley leaves mediated biosynthesis of Au nanomaterials as a potential contrast agent for computed tomography imaging

Over the past few years, environment-friendly green synthetic methods for metal nanoparticles(NPs) have received considerable attention. The use of plant extracts is considered as potential for the biosynthesis of metal NPs due to its easier obtainment, cheap accessibility to industrial scale-up and high biosecurity. Herein, with the aqueous leaf extract of barley leaves as the template, we reported a rapid, single step, cost-effective and eco-friendly synthetic route to prepare new gold nanoparticles(BL-Au NPs).Significantly, except for the key role as the reducing, barley leaves was further utilized as the capping agent that ensure the stability of the BL-Au NPs. The characterization results of TEM, FTIR and UV-vis indicated that the gold nanoparticles coated with barley leaves extract were successfully synthesized. In vitro and zebra fish toxicity and stability assays demonstrated its good biocompatibility and high colloidal stability. The CT images in vitro demonstrated that the constructed BL-Au NPs possessed superiority in X-ray attenuation ability compared to clinically commonly used iodinated small molecular contrast agent. And BL-Au NPs can be used as contrast agent for effective CT imaging of zebra fish model. These results suggest the potential utility of BL-Au NPs as a CT imaging contrast agent in clinical CT imaging based diagnosis.

Surface modification of phosphate ion to promote photocatalytic recovery of precious metals

Photocatalytic recovery,a novel precious metal recycling technology,dedicates to solving the environmental and energy consumption problems caused by traditional technologies.The activation of molecular oxygen (O_(2)) is one of the most critical steps in the whole process.Herein,we regulated the different adsorption intensity of oxygen on the surface by designing phosphate (PO_(4)^(3-)) modified titanium oxide(TiO_(2)).The results show that the adsorption of oxygen on the photocatalyst surface is gradually enhanced,which effectively improves the dissolution rate of precious metals.PO_(4)^(3-)modification increased the photocatalytic dissolution rate of gold (Au) by 2.8 times.The photocatalytic activity of other precious metals dissolution (such as palladium (Pd),platinum (Pt),rhodium (Rh),ruthenium (Ru) and iridium (Ir)) was also significantly improved.It is applied to the recovery of precious metals from spent catalysts and electronic devices to significantly promote the recovery efficiency.This indicates the direction for designing more efficient photocatalysts for precious metal recovery.

Photothermally Enhanced Dual Enzyme-mimic Activity of Gold-Palladium Hybrid Nanozyme for Cancer Therapy

Based on characteristics of the tumor microenvironment(TME),including acidity,hypoxia,inflammation and hydrogen peroxide overload,combined with emerging nanotechnologies,designing nanoplatforms with TME specificity/responsiveness for tumor treatment is a promising nanotherapeutic strategy.In this work,a multifunctional gold-palladium bimetallic cascade nanozyme was constructed for effective photothermal-enhanced cascade catalyzed synergistic therapy of tumors.The dumbbell-like Au-Pd bimetallic nanomaterial(Au NRs-Pd@HA)was obtained by reducing palladium on gold nanorods with ascorbic acid(AA)and further modified with hyaluronic acid(HA).The introduction of HA brings biocompatibility and targeting properties.The zebrafish embryos model showed that Au NRs-Pd@HA had good biocompatibility and low biotoxicity.Au NRs-Pd@HA can induce catalytic conversion of glucose to generate H_(2)O_(2) efficiently,and subsequently undergo cascade reaction to produce abundant·OH radicals,exhibiting peroxidase-like(POD-like)and glucose oxidase-like(GOD-like)capabilities.The generated·OH was a key factor for tumor ablation.Meanwhile,Au NRs-Pd@HA exhibits good photothermal performance under 808 nm irradiation,in favor of photothermal therapy(PTT).Especially,the POD-like and GOD-like activities were significantly enhanced due to the photothermal effect.The synergistic PTT and photothermal-enhanced nanozymes with cascade catalytic effect enabled efficient and safe cancer therapy.

Microwave assisted synthesis of PQ-GDY@NH_(2)-UIO-66(Zr) for improved photocatalytic removal of NOx under visible light

Pyrazinoquinoxaline-based graphdiyne (PQ-GDY) contains a fixed number of sp-sp2hybridized carbon atoms and pyrazine-like sp2hybridized N atoms.In this paper,NH_(2)-UIO-66(Zr) on PQ-GDY substrate was successfully constructed with the help of microwaveassisted heating.PQ-GDY surface acts as a microwave antenna under microwave irradiation to rapidly absorb microwave energy and form hot spots (hot spot effect),which facilitates the formation of well-dispersed NH2-UIO-66(Zr) with good crystallinity.Transient absorption spectra show that high hole transport property of PQ-GDY can accelerate the migration of photogenerated holes from NH2-UIO-66(Zr) to PQ-GDY and greatly reduce the recombination rate of photogenerated electrons and holes due to the strong interaction between PQ-GDY and NH2-UIO-66(Zr).Under visible light (λ≥420 nm),PQ-GDY@NH_(2)-UIO-66(Zr) shows high photocatalytic stability and high NO_(x)removal rate up to 74%,which is 44% higher than that of primitive NH_(2)-UIO-66(Zr).At the same time,it inhibits the formation of toxic byproducts (NO2) and limits its concentration to a low level.

Highly selective and efficient photocatalytic NO removal:Charge carrier kinetics and interface molecular process

The widespread nitrogen oxides(NOx,mainly in NO)in the atmosphere have threatened human health and ecological environment.The dilute NO(ppb)is difficult to efficiently remove via the traditional process due to its characteristics of low concentration,wide range,large total amount,etc.Photocatalysis can utilize solar energy to purify NO pollutants under mild conditions,but its application is limited due to the low selectivity of nitrate and poor activity of NO removal.The underlying reason is that the interface mechanism of NO oxidation is not clearly understood,which leads to the inability to accurately regulate the NO oxidation process.Herein,the recent advances in the photocatalytic oxidation of NO are summarized.Firstly,the common strategies to effectively regulate carrier dynamics such as morphology control,facet engineering,defect engineering,plasma coupling,heterojunction and single-atom catalysts are discussed.Secondly,the progress of enhancing the adsorption and activation of reactants such as NO and O_(2) during NO oxidation is described in detail,and the corresponding NO oxidation mechanisms are enumerated.Finally,the challenges and prospects of photocatalytic NO oxidation are presented in term of nanotechnology for air pollution control.This review can shed light on the interface mechanism of NO oxidation and provide illuminating information on designing novel catalysts for efficient NOx control.

Photoelectrocatalytic reduction of CO_2 to methanol over a photosystem Ⅱ-enhanced Cu foam/Si-nanowire system

A solar-light double illumination photoelectrocatalytic cell（SLDIPEC） was fabricated for autonomous CO2 reduction and O2 evolution with the aid of photosystem II（PS-II, an efficient light-driven water-oxidized enzyme from nature） and utilized in a photoanode solution. The proposed SLPEC system was composed of Cu foam as the photoanode and p-Si nanowires（Si-NW） as the photocathode. Under solar irradiation, it exhibited a super-photoelectrocatalytic performance for CO2 conversion to methanol, with a high evolution rate（41.94 mmol/hr）, owing to fast electron transfer from PS-II to Cu foam.Electrons were subsequently trapped by Si-NW through an external circuit via bias voltage（0.5 V）, and a suitable conduction band potential of Si（-0.6 e V） allowed CO2 to be easily reduced to CH3 OH at the photocathode. The constructed Z-scheme between Cu foam and Si-NW can allow the SLDIPEC system to reduce CO2（8.03 mmol/hr） in the absence of bias voltage. This approach makes full use of the energy band mismatch of the photoanode and photocathode to design a highly efficient device for solving environmental issues and producing clean energy.

Advanced protein adsorption properties of a novel silicate-based bioceramic: A proteomic analysis

Silicate bioceramics have been shown to possess excellent cytocompatibility and osteogenic activity,but the exact mechanism is still unclear.Protein adsorption is the first event taking place at the biomaterial-tissue interface,which is vital to the subsequent cellular behavior and further influence the biomaterial-tissue interaction.In this work,the protein adsorption behavior of a novel CPS bioceramic was evaluated using the proteomics technology.The results showed that CPS adsorbed more amount and types of serum proteins than HA.FN1 and IGF1 proteins selected from proteomics results were validated by Western-blot experiment.Pathway analysis also revealed mechanistic insights how these absorbed proteins by CPS help mediate cell adhesion and promotes osteogenic activity.Firstly,the dramatically enhanced adsorption of FN1 could greatly promote cell adhesion and growth.Secondly,IGF1 was uniquely adsorbed on CPS bioceramic and IGF1 could activate Rap1 signaling pathway to promote cell adhesion.Thirdly,the increased adsorption of FN1,IGF1 and COL1A2 proteins on CPS explains its better ability on bone regeneration than HA.Fourthly,the increased adsorption of IGF1,CHAD,COL2A1 and THBS4 proteins on CPS explains its ability on cartilage formation.Lastly,the increased adsorption of immunological related proteins on CPS may also play a positive role in bone regeneration.In addition,CPS had a much better cell adhesion ability than HA,proving that more adsorbed proteins really had a positive effect on cell behavior.The more adsorbed proteins on CPS than HA might indicated a better bone regeneration rate at early stage of implantation.

Double-edged effects caused by magnesium ions and alkaline environment regulate bioactivities of magnesium-incorporated silicocarnotite in vitro

Magnesium(Mg)is an important element for its enhanced osteogenic and angiogenic properties in vitro and in vivo,however,the inherent alkalinity is the adverse factor that needs further attention.In order to study the role of alkalinity in regulating osteogenesis and angiogenesis in vitro,magnesium-silicocarnotite[Mg-Ca5(PO4)2SiO4,Mg-CPS]was designed and fabricated.In this study,Mg-CPS showed better osteogenic and angiogenic properties than CPS within 10wt.%magnesium oxide(MgO),since the adversity of alkaline condition was covered by the benefits of improved Mg ion concentrations through activating Smad2/3-Runx2 signaling pathway in MC3T3-E1 cells and PI3K-AKT signaling pathway in human umbilical vein endothelial cells in vitro.Besides,provided that MgO was incorporated with 15wt.%in CPS,the bioactivities had declined due to the environment consisting of higher-concentrated Mg ions,stronger alkalinity and lower Ca/P/Si ions caused.According to the results,it indicated that bioactivities of Mg-CPS in vitro were regulated by the double-edged effects,which were the consequence of Mg ions and alkaline environment combined.Therefore,if MgO is properly incorporated in CPS,the improved bioactivities could cover alkaline adversity,making Mg-CPS bioceramics promising in orthopedic clinical application for its enhancement of osteogenesis and angiogenesis in vitro.

Microwave-assisted synthesis of oxygen vacancy associated TiO_(2)for efficient photocatalytic nitrate reduction

The solar-driven photocatalytic technology has shown great potential in nitrate(NO_(3)^(-))pollutants reduction,however,it has been greatly hindered by the complex preparation and high cost of photocatalysts.Herein,a relatively low-cost photocatalyst,rutile and anatase mixed phase TiO_(2) was synthesized by a facile microwave-hydrothermal method.Meanwhile,oxygen vacancy is successfully generated,leading to an acidic surface for strong adsorption towards NO_(3)^(-),which further improved the reduction activity.Compared with the commercial P25,a higher NO_(3)^(-) conversion of ca.100%and nitrogen(N_(2)) selectivity of 87%were achieved under UV(365 nm)irradiation within 2 h.This research provides a promising strategy for designing efficient noble metal free photocatalyst in the NO_(3)^(-) reduction.

Discovery of New Thioviridamide-Like Compounds with Antitumor Activities

Thioviridamide is a structurally unique compound with potent antitumor activity.The biosynthesis of thioviridamide follows a typical pathway as ribosomally synthesized and post-transiationally modified peptides,making the genome mining-based discovery of thioviridamide-like compounds rational.Taking advantage of the linkage between the precursor peptide and the metabolite skeleton,we identified a new biosynthetic gene cluster in Streptomyces sp.NRRL S-87 that could encode thioviridamide analogues.Overexpression of the whole gene cluster led to the isolation and structure elucidation of TVA-YJ-4 and TVA-YJ-5,two novel thioviridamide-like compounds featuring N-terminal capping groups.Chemical screening of the fermentation extracts also detected TVA-YJ-6,another new thioviridamide-like compound with representative methionine sulfoxide.Detailed analysis further revealed that these structural modifications were introduced during the compound extraction process instead of through genuine enzymatic reactions.TVA-YJ-4 and TVA-YJ-5 display slightly reduced cytotoxic activities against a panel of tumor cell lines in comparison with their parental natural product,TVA-YJ-2.Our work will expand the membership of this rare class of compounds and promote related biosynthetic studies.