Synthesis,Design And Water Oxidation Catalytic Performance Of Transition Metal Based Catalysts

In order to solve the problems of serious energy crisis and environmental pollution caused by the burning of fossil fuels,scientists regardwater splitting to generate hydrogen fuels and oxygen by simulation photosynthesis as one of the most promising and attractive strategies to accomplish the conversion from solar/electric energy to chemical energy.As a result of the luggish kineics,water oxidation is the bottleneck of water splitting.So researches are concentrated on the developments of efficient,cheap and stable water oxidation catalysts.The first-transition mental oxide is a kind of potential water oxidation catalysts,receivedextensive attention.As the exploration of this kind of materials,the reserachers focus on the mechanism of water oxidation,in order to guide the practice with theory and to further improve its catalystic activities.On the other hand,polyoxomentalate?POM?with transition metal as homogeneous catalyst attract wide attentionin mechanism research.The all inorganic coordination structures of POM make that they can withstand the strong oxidizing environment during the process of water oxidation.Co?Ni?Cu and other transition metal atom with the absence of ligand show the unique physical and chemical properties.The main content of this article include the research of???Co/Cu transition metal oxides as electro/photocatalytic water oxidation and the preliminary exploration of Co,Cu,Ni,Zn and Mn replaced POM as photocatalytic water oxidation catalysts:1.We reported the novel kind of porous Co₃O₄/CuO hollow polyhedral nanocages?HPNCs?materials derived from MOF.The effect of Co/Cu molar ratio in porous Co₃O₄/CuO HPNCs on the photocatalytic water oxidation was discussed in detail.In the system of Ru?bpy?3²⁺/visible-light/Na₂S₂O₈ photocatalytic water oxidation,the catalytic activities of these materials were performed.Heterojunctions of Co₃O₄/CuO HPNCs enhance charge separation by an internal electric field,which improves the photocatalytic O2 evolution activity.2.We reported a series of materials with similar morphology of hollow polyhedral nanocages?HPNCs?: Cu-ZIF-T(Cu_0.2Co_2.8O₄),CuO/Co₃O₄ and Co₃O₄ to explore the influences of different modified methods on the catalytic performance for electrocatalytic and photocatalytic water oxidation reaction.Catalyst Cu-ZIF-400 with Cu²⁺ incorporated in Co₃O₄ crystal lattice and the catalyst CuO/Co₃O₄ with CuO loading on the Co₃O₄ performed better catalytic activities than Co₃O₄ in the water oxidation reaction.At the same time,by varying the calcination temperature,the catalysts of Cu-ZIF-T showed distinguishable catalytic activities.3.We synthesis a series POM with different transition metal as water oxidation catalysts [M2?B-?-SiW8O31?2]16-(M=Cu²⁺/Co²⁺/Mn²⁺/Ni²⁺/Zn²⁺).In the system of Ru?bpy?3²⁺/visible-light/Na₂S₂O₈ water oxidation,the catalytic activities of these catalysts were performed.The experiments result demonstrated that POMs with different transition metals have different water oxidation catalytic activities.