CdTe/CdSe-sensitized photocathode coupling with Ni-substituted polyoxometalate catalyst for photoelectrochemical generation of hydrogen

In terms of photoelectrochemical(PEC)hydrogen evolution,substantial challenge still remains regarding the controllable fabrication of quantum dots(QDs)-sensitized photocathodes with enhanced visible-light absorption,efficient charge carrier separation,and directional migration at the electrode interface.In this work,the CdTe/CdSe QDs-sensitized photocathodes were delicately constructed on p-type NiO-coated indium tin oxide(ITO)electrodes by spin-coating approach.The resulting co-sensitized photocathode exhibits a favorable pseudo-Type Ⅱ energetic band alignment that combines the advantages of strong light absorption of constituent QDs as well as the effective and oriented charge separation and migration.Upon green LED light illumination,the photogenerated electrons could be effectively transferred to a tetra-nickel-substituted polyoxometalate catalyst for hydrogen production while photogenerated holes will be scavenged at the NiO/ITO electrode.Under minimally optimized conditions,the pseudo-Type Ⅱ CdTe/CdSe-sensrtized photocathode yields a photcx:urrent density of over 100 pA/cm^(2) and a Faradaic efficiency of〜100%,which is among one of the most efficient QDs-based photocathode systems coupling with Ni-substituted polyoxometalate catalyst for photoelectrochemical hydrogen generation.

Optimization of CdSe Quantum Dots Sensitized TiO_2 Photo Anodes in Fabrication of Quantum Dots Sensitized Solar Cells

As one of the most promising candidates for the third generation solar cells,quantum dots sensitized solar cells(QDSCs) have been comprehensively studied.In this work,we synthesize the CdSe QDs with the absorption range from 450-550 nm,which are suitable to be applied in the QDSCs.Then,we found that the self-assembly(SA) deposition method is superior to the successive ionic layer adsorption and reaction(SILAR) deposition method in the fabrication of the photo anodes.Furthermore,the influence of TiO_2's thickness of the photo anodes to the QDSCs' efficiency has been studied.With the optimized CdSe QDs sensitized photo anodes,the efficiency of the QDSCs can reach 3.38%in this work.