Regulating the interfacial charge transfer and constructing symmetry-breaking sites for the enhanced N_(2) electroreduction activity

The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,while the challenge associated with N_(2) activation highlights the demand for efficient electrocatalysts.Herein,we demonstrate that PdCu nanoparticles with different Pd/Cu ratios anchored on boron nanosheet(PdCu/B)behave as efficient NRR electrocatalysts toward NH_(3) synthesis.Theoretical and experimental results confirm that the highly efficient NH_(3) synthesis can be achieved by regulating the charge transfer between interfaces and forming a symmetry-breaking site,which not only alleviates the hydrogen evolution but also changes the adsorption configuration of N_(2) and thus optimizes the reaction pathway of NRR over the separated Pd sites.Compared with monometallic Pd/B and Cu/B,the PdCu/B with the optimized Pd/Cu ratio of 1 exhibits superior activity and selectivity for NH_(3) synthesis.This study provides new insight into developing efficient catalysts for small energy molecule catalytic conversion via regulating the charge transfer between interfaces and constructing symmetry-breaking sites.

Interfacial Charge Transfer Induced Electronic Property Tuning of MoS_2 by Molecular Functionalization

The modulation of electrical properties of MoS_2 has attracted extensive research interest because of its potential applications in electronic and optoelectronic devices.Herein,interfacial charge transfer induced electronic property tuning of MoS_2 are investigated by in situ ultraviolet photoelectron spectroscopy and x-ray photoelectron spectroscopy measurements.A downward band-bending of MoS_2-related electronic states along with the decreasing work function,which are induced by the electron transfer from Cs overlayers to MoS_2,is observed after the functionalization of MoS_2 with Cs,leading to n-type doping.Meanwhile,when MoS_2 is modified with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F_4-TCNQ),an upward band-bending of MoS_2-related electronic states along with the increasing work function is observed at the interfaces.This is attributed to the electron depletion within MoS_2 due to the strong electron withdrawing property of F_4-TCNQ,indicating p-type doping of MoS_2.Our findings reveal that surface transfer doping is an effective approach for electronic property tuning of MoS_2 and paves the way to optimize its performance in electronic and optoelectronic devices.

Rationally construction of atomic-precise interfacial charge transfer channel and strong build-in electric field in nanocluster-based Zscheme heterojunctions with enhanced photocatalytic hydrogen production

The lack of effective charge transfer driving force and channel limits the electron directional migration in nanoclusters(NC)-based heterostructures,resulting in poor photocatalytic performance.Herein,a Z-scheme NC-based heterojunction(Pt1Ag28-BTT/CoP,BTT=1,3,5-benzenetrithiol)with strong internal electric field is constructed via interfacial Co-S bond,which exhibits an absolutely superiority in photocatalytic performance with 24.89 mmol·h^(−1)·g−1 H_(2)production rate,25.77%apparent quantum yield at 420 nm,and~100%activity retention in stability,compared with Pt1Ag28-BDT/CoP(BDT=1,3-benzenedithiol),Ag29-BDT/CoP,and CoP.The enhanced catalytic performance is contributed by the dual modulation strategy of inner core and outer shell of NC,wherein,the center Pt single atom doping regulates the band structure of NC to match well with CoP,builds internal electric field,and then drives photogenerated electrons steering;the accurate surface S modification promotes the formation of Co-S atomic-precise interface channel for further high-efficient Z-scheme charge directional migration.This work opens a new avenue for designing NC-based heterojunction with matchable band structure and valid interfacial charge transfer.

Rational Design of LDH/Zn_(2)SnO_(4) Heterostructures for Efficient Mineralization of Toluene Through Boosted Interfacial Charge Separation

It is crucial to efficiently separate and transport photo-induced charge carriers for the effective implementation of photocatalysis toward environmental remediation.A rational design strategy is proposed to validate such proposition through the construction of an interfacial structure in the form of LDH/Zn_(2)SnO_(4) heterostructures in this research.The interfacial charge transfer on LDH/Zn_(2)SnO_(4) is greatly promoted via the unique charge transfer pathway,as characterized by transient photocurrent responses,X-ray photoelectron spectroscopy,electron paramagnetic resonance spectrum,and photoluminescence analysis.As such,it contributes to the generation of reactive oxygen species(ROS)and the activation of reactants for the mineralization of toluene.According to the in situ DRIFTS spectra analysis,the accumulation of benzoic acid takes place possibly through the partial oxidation of the methyl group on toluene at the interface of the LDH/Zn 2 SnO 4 heterostructure.This process can greatly promote the photocatalytic oxidation of toluene with the enhanced ring-opening efficiency.The LDH/Zn 2 SnO 4 is thus demonstrated as superior photocatalyst against toluene(removal efficiency of 89.5%;mineralization of 83.1%;and quantum efficiency of 4.55×10^(−6) molecules/photon).As such,the performance of this composite far exceeds that of their individual components(e.g.,P25,pure Mg-Al LDH,or Zn_(2)SnO_(4)).This study is expected to offer a new path to the interfacial charge transfer mechanism based on the design of highly efficient photocatalysts for air purification.

Light-Induced Charge Transfer at Interface Between Lipid-Free RhTSPc Film and p-Si(111)

The present paper covers the lipid-free rhodium tetrasulfonato-phthalocyanine (RhTSPc) films prepared on p-Si(111) by using Langmuir-Blodgett technique. Their surface photovoltage spectra were measured. It was found that there is a strong interaction at the interface between the RhTSPc film and p-Si (111) and that the surface photovoltaic effect of the film system is maximum when only one monolayer of RhTSPc molecules coats p-Si(111), which is similar to that of CuTSPc films on p-Si(111) reported previously. These results confirm that only the monolayer of dye molecules being adjacent to the semiconductor surface plays a key role in the light-induced interfacial charge transfer process.

Rational design of Ce-doped CdS/N-rGO photocatalyst enhanced interfacial charges transfer for high effective degradation of tetracycline

The charge carrier separation efficiency and the adsorption capacity of the photocatalyst usually affect the degradation rate of antibiotics.Herein,Cerium-doped leaf-like CdS(Ce-CdS)modified with ultrathin N-doped rGO(N-rGO)composites were successfully constructed(Ce-CdS/N-rGO)to investigate the removal efficiency of tetracycline(TC).X-ray photoelectron spectroscopy(XPS)and photoelectrochemical results revealed that Ce ions doped in CdS acting as the electron capture sites facilitated the interfacial charge transfer.Theoretical calculation(DFT)results indicated that the interfacial effect between Ce-CdS and ultrathin N-rGO promoted the transfer of photogenerated electrons under the synergistic effect between the doping and interface modification strategy.The optimized Ce5-CdS/N-rGO20 composites had the maximum TC removal capability(94.5%)and maintained a stable cycling performance.In addition,the adsorption-driven photocatalytic degradation pathway of TC was studied through mass spectrometry(MS)and in-situ Fourier transform infrared spectroscopy(in-situ FTIR).This study will provide an effective strategy for the construction of efficient photocatalytic composites for wastewater treatment.

D^(6h)Symmetric Radical Donor-Acceptor Nanographene Modulated Interfacial Carrier Transfer for High-Performance Perovskite Solar Cells

Imbalanced charge-carrier extraction remains an issue aggravating interfacial charge accumulation and recombination.More hopping transport channels could accelerate the extraction of charge.Here,we demonstrated an effective“bridging interface”strategy between the perovskite/2,2′,7,7′-tetrakis(N,N-di-pmethoxyphenylamine)-9,9′-spirobifluorene(spiro-OMeTAD)that modulates interfacial charge transfer and improves hole mobility using radical-containing donor-acceptor nanographenes(D-A NGs)possessing electron-deficient perchlorinated NGs and electron-rich aniline derivatives.The fully delocalized backbone of nanographene formed a conjugated bridge for intermolecular charge transfer and generated stable radical cations,verified by electron spin resonance.Lamellar andπ-πstacking orientation of D-A NGs also provided advantageous hopping transport channels.Besides favorable charge transfer within D-A NGs,systematic explorations indicated a strong interface coupling and noticeable charge transfer across the D-A NGs and perovskite interface,where electrons would flow from D-A NGs to perovskite,and holes would flow from perovskite to D-A NGs.Moreover,the hole mobility of spiro-OMeTAD was also enhanced because the D-A NGs would diffuse into the spiro-OMeTAD layer.As a result,planar n-i-p perovskite solar cellsmodified byD-ANG-OMe/D-ANG-tBudeliveredchampion power conversion efficiencies(PCEs)of 23.25%and 23.51%,respectively.

Facile template-induced synthesis of Ag-modified TiO_2 hollow octahedra with high photocatalytic activity

Noble metal/titania hollow nanomaterials usually exhibit excellent photocatalytic activity because of their high specific surface area,low density,good surface permeability,strong light-harvesting capacity,and rapid interfacial charge transfer. However,the present preparation methods usually include complicated and multistep procedures,which can cause damage to the hollow nanostructures. In this paper,a facile template-induced synthesis,based on a template-directed deposition and in situ template-sacrificial dissolution,was employed to prepare Ag-modified TiO 2（Ag/TiO 2） hollow octahedra using Ag2 O octahedra as templates and TiF 4 as the precursor. In the synthetic strategy,the shells of TiO 2 hollow octahedra were formed by coating TiO 2 nanoparticles on the surface of Ag2 O templates based on the template-directed deposition. Simultaneously,the Ag2 O templates can be in situ removed by dissolving the Ag2 O octahedral template in HF solution produced via the hydrolysis reaction of TiF 4 in the reaction system. In addition,Ag nanoparticles were deposited on the inside and outside surfaces of TiO 2 shells by effectively using the photosensitive properties of Ag2 O and Ag＋ ions under light irradiation,along with the formation of TiO 2 hollow octahedra. The Ag/TiO 2 hollow octahedra exhibited high photocatalytic activity because of their（1） short diffusion distances between photogenerated electrons and holes because of the thin shells of Ag/TiO 2 hollow octahedral,（2） deposition of Ag nanoparticles on the inside and outside surfaces of TiO 2 shells,and（3） rapid interfacial charge transfer between TiO 2 shells and Ag nanoparticles. This work may also provide new insights into preparing other Ag-modified and hollow nanostructured photocatalysts.

Redox-assisted Li^+-storage in lithium-ion batteries

Interfacial charge transfer is the key kinetic process dictating the operation of lithium-ion battery. Redox-mediated charge propagations of the electronic （e- and h＋ ） and ionic species （Li＋） at the electrode-electrolyte interface have recently gained increasing attention for better exploitation of battery materials. This article briefly summarises the energetic and kinetic aspects of lithium-ion batteries, and reviews the recent progress on various redox-assisted Li＋ storage approaches. From molecular wiring to polymer wiring and from redox targeting to redox flow lithium battery, the role of redox mediators and the way of the redox species functioning in lithium-ion batteries are discussed.

Atomically precise Au_(25)(GSH)_(18)nanoclusters versus plasmonic Au nanocrystals:Evaluating charge impetus in solar water oxidation

Atomically precise metal nanoclusters(NCs)have been deemed as an emerging class of metal nanomaterials owing to fascinating size-dependent physicochemical properties,discrete energy band structure,and quantum confinement effect,which are distinct from conventional metal nanoparticles(NPs).Nevertheless,metal NCs suffer from photoinduced self-oxidative aggregation accompanied by in-situ transformation to metal NPs,markedly reducing the photosensitization of metal NCs.Herein,maneuvering the generic instability of metal NCs,we perform the charge transport impetus comparison between atomically precise metal NCs and plasmonic metal NPs counterpart obtained from in-situ self-transformation of metal NCs in photoelectrochemical(PEC)water splitting reaction.For conceptual demonstration,we proposed two quintessential heterostructures,which include TNTAs-Au_(25)heterostructure fabricated by electrostatically depositing glutathione(GSH)-protected Au_(25)(GSH)_(18)NCs on the TiO_(2)nanotube arrays(TNTAs)substrate,and TNTAs-Au heterostructure constructed by triggering self-transformation of Au_(25)(GSH)_(18)NCs to plasmonic Au NPs in TNTAs-Au_(25)via calcination.The results indicate that photoelectrons produced over Au_(25)NCs are superior to hot electrons of plasmonic Au NPs in stimulating the interracial charge transport toward solar water oxidation.This is mainly ascribed to the significantly accelerated carrier transport kinetics,prolonged carrier lifespan,and substantial photosensitization effect of Au_(25)NCs compared with plasmonic Au NPs,resulting in the considerably enhanced PEC water splitting performance of TNTAs-Au_(25)relative to plasmonic TNTAs-Au counterpart under visible light irradiation.Our work would provide important implications for rationally designing atomically precise metal NCsbased photosystems toward solar energy conversion.

多重非共价构象锁与π桥工程相结合用于开发Y系列受体

非共价构象锁(NCLs)策略被广泛用于构建高性能有机半导体.从分子层面深入探索NCLs对有机光电受体材料和界面的影响,有助于开发高性能光电材料.本文提出了通过整合NCLs和π桥的策略,开发了三种新型Y系列受体(YO、YS、YSe)来增强分子性能,并揭示了NCLs在有机光电受体材料中的作用机制.通过分析,我们首次发现,在适当的位置引入π桥不仅可在骨架内形成多重NCLs,也可与翼链形成NCLs,进一步增强受体的平面性和刚性,从而有助于增强光吸收和减少能量损失.此外,除电荷转移方向改善外,新体系电荷转移态的比例分别增加了8%、20%和36%,助力界面电荷分离.本工作通过π桥工程引入多重NCL,改善受体材料光电性能和界面特性,有望提高有机光伏器件的光电转换效率.

Electrostatic self-assembly of 2D/2D CoWO_(4)/g-C_(3)N_(4)p-n heterojunction for improved photocatalytic hydrogen evolution:Built-in electric field modulated charge separation and mechanism unveiling

Two-dimensional(2D)semiconductor heterojunctions are considered as an effective strategy to achieve fast separation of photoinduced carriers.Herein,a novel CoWO_(4)/g-C_(3)N_(4)(CWO/CN)p–n junction was synthesized using an electrostatic selfassembly method.The constructed 2D/2D p–n heterostructure had a rich hetero-interface,increased charge density,and fast separation efficiency of photoinduced carriers.The in-situ Kelvin probe force microscopy confirmed that the separation pathway of photoinduced carriers through the interface obeyed an II-scheme charge transfer mechanism.Experimental results and density functional theory calculations indicated the differences of work function between CWO and CN induced the generation of built-in electric field,ensuring an efficient separation and transfer process of photoinduced carriers.Under the optimized conditions,the CWO/CN heterojunction displayed enhanced photocatalytic H_(2)generation activity under full spectrum and visible lights irradiation,respectively.Our study provides a novel approach to design 2D/2D hetero-structured photocatalysts based on p–n type semiconductor for photocatalytic H_(2)generation.

A Z-scheme LaFeO_(3)-CuFe_(2)O4 composite for sulfate radical-based photocatalytic process:Synergistic effect and mechanism

The sulfate radical-based photocatalytic process is supposed to be the most promising way to degrade organic pollutants.However,the development of a suitable and efficient photocatalyst is very challenging.The 40LaFeO_(3)-CuFe_(2)O_(4)(40LFO-CFO)nanocomposite was constructed and its catalytic performance was studied using Rhodamine B(RhB)as the target pollutant.40LFO-CFO exhibited excellent RhB degradation by the persulfate(PS)-assisted photocatalytic process compared to the pristine LFO and CFO.The degradation rate constant for RhB by 40LFO-CFO in the Vis/PS system was 2.22h^(-1)which is 3.04 times and 5.05 times higher than the pristine LFO(0.73 h^(-1))and CFO(0.44h^(-1)),respectively.Furthermore,the trapping experiments and EPR spectra proved that h^(+) plays a leading role in the bleaching of RhB for the 40LFO-CFO/PS/Vis system.The enhanced photocatalytic oxidation activity of 40LFO-CFO could be attributed to the unique charge carriers flow in 40LFO-CFO due to the Z-scheme and the cooperation effect between photocatalysis and PS activation.The recycle tests confessed the stability of 40LFO-CFO.Additionally,the intermediates and products of RhB are detected by liquid chromatographymass spectrometry(LC-MS),and the photocatalytic degradation routes of RhB for the 40LFO-CFO/Vis/PS system were proposed.Moreover,the 40LFO-CFO nanocomposite has a superior catalytic performance for other organics,suggesting that it is a promising heterocatalyst because of its high catalytic activity and stability for the PS-assisted photocatalytic process.

2D/2D hierarchical Co_(3)O_(4)/ZnIn_(2)S_(4)heterojunction with robust builtin electric field for efficient photocatalytic hydrogen evolution

Because of its importance in enhancing charge separation and transfer,built-in electric field engineering has been acknowledged as an effective technique for improving photocatalytic performance.Herein,a stable p–n heterojunction of 2D/2D(2D:twodimensional)Co_(3)O_(4)/ZnIn_(2)S_(4)with a strong built-in electric field is precisely constructed.The Co_(3)O_(4)/ZnIn_(2)S_(4)heterojunction exhibits a higher visible-light photocatalytic hydrogen(H2)evolution rate than the individual components,which is primarily attributed to the synergy effect of improved light absorption,abundant active sites,short charge transport distance,high separation efficiency of photogenerated carriers.Furthermore,the photoelectrochemical studies and density functional theory(DFT)calculation results demonstrate that the enhanced interfacial charge separation and migration induced by the generated built-in electric field are the critical reasons for the boosted photocatalytic performance.This research might pave the way for the rational design and manufacturing of 2D/2D heterojunction photocatalysts with extremely efficient photocatalytic performance for solar energy conversion.

Enhanced Photocatalytic Performance of Surface-Modified TiO_(2) Nanofibers with Rhodizonic Acid

The improvement of the photocatalytic performance of TiO_(2) nanofibers(NFs),prepared by electrospinning,is achieved by surface modification with the rhodizonic acid(RhA).The condensation reaction between hydroxyl groups from TiO_(2) NFs and RhA is accompanied by the red-shift of optical absorption due to interfacial charge transfer(ICT)complex formation.Crystal structure,morphology,and optical properties of unmodified and surface-modified TiO_(2) NFs were analyzed.The photocatalytic performance of prepared samples has been examined through degradation of organic dye methylene blue.Superior photocatalytic activity of surface-modified TiO_(2) NFs with RhA is attributed to their enhanced optical properties,i.e.,the ability to harvest the photon energy in the visible spectral range.