Study On Photoelectrocatalytic Hydrogen Evolution And CO₂ Reduction Of Nickel And Copper Complex

One of the most appealing strategies to address the problems of global warming and energy shortage is to develop clean and sustainable energy source.To this end,considerable efforts have been devoted to designing well-defined catalysts for energy conversion.Although the water reduction and CO₂ reduction offer a promising prospect for the conversion and storage of solar energy or electricity,the related reactions involve multi-electron or proton transfers and driving these reactions requires considerable overpotentials.The utilization of proper catalysts can accelerate the multiple electron or proton transfers in these reactions and thus promote the progress of these reactions.The mainly works:1.[Ni^??ATSM?],a new catalyst for hydrogen production was synthesized.Under photoirradiation with blue light??=469 nm?,together with Cd S nanorods as a photosensitizer,and ascorbic acid as a sacrificial electron donor,the nickel complex can photocatalyze hydrogen evolution with a turnover number of 11,500 mol H₂ per mol of catalyst(mol of cat^-1)during 80 h irradiation in a heterogeneous environment.2.Electrochemical investigations show that[Ni^??ATSM?]can catalyze methanol generation from a CO₂-saturated buffer with a Faradaic efficiency of 88%during a 2 h electrolysis.Under blue light,together with Au-Cd S nanoclusters as a photosensitizer,and ascorbic acid as a sacrificial electron donor,[Ni^??ATSM?]exhibits a high turnover number over 7,857 for methanol generation with a selectivity of 85.86%during 40 h irradiation.The highest apparent quantum yield is 21.62%.Under the same conditions,the photocatalytic system with Cd S nanorods as a photosensitizer provides methanol with a turnover number of 11,700,a selectivity of 42.23%and an apparent quantum yield of 16.15%.Compared with Cd S nanorods,Au-Cd S nanoclusters exhibits a much higher selectivity for methanol generation via CO₂ reduction.3.We described new catalytic systems based on the copper complex,[Cu^??ATSM?],for electrochemical and photochemical driven CO₂ reduction to methanol.As an electrocatalyst,this copper complex can catalyse methanol generation from a CO₂-saturated buffer with a Faradaic efficiency of 74%during a 2 h electrolysis.The photochemical studies showed that under blue light,the three-component photocatalytic system containing Au-Cd S nanoclusters,ascorbic acid,and[Cu^??ATSM?]can catalyze methanol generation from CO₂ reduction and can work for about 40 h.[Cu^??ATSM?]can catalyse methanol generation with a turnover number of4,067 moles of methanol per mole of catalyst(mol of cat^-1)and a methanol selectivity of 74%.The highest apparent quantum yield is 9.0%.