| Hydrogen is a kind of renewable,efficiently and clean energy,water is the only product of combustion when hydrogen combines with oxygen.Artificial photosynthesis water splitting is the most ideal energy conversion way to generate hydrogen.Photolysis of water is composed of two half-reactions: the reduction of protons to hydrogen and the oxidation of water to oxygen.The water oxidation is considered the most challenging step of overall water splitting because it requires a multielectron stepwise building up of very high redox potentials.Therefore,develepment of efficient and stable water oxidation catalysts?WOCs?becomes the key in overall water splitting.This paper was divided into three parts including the researchs on photocatalysts containing the less-expensive transition metal Co.The water oxidation catalytic activities and the stability of the as-prepared catalysts were systematically investigated.These results further expand the field of water oxidation catalysts based on the non-noble metal Co.These researchs also provide valuable references for the development of highly efficient and stable water oxidation catalyst.1.Stable Co@CoO core-shell nanocrystals were prepared via a one-pot toluene-water two-phase interfacial reaction,and these products were investigated as water oxidation catalysts for oxygen evolution under visible light irradiation.To obtain the optimal conditions,we systematically investigated the variables of photocatalytic reaction,including pH,buffer types,and photosensitizers.Multiple experiments including DLS,XRD,XPS,LC-MS were applied to investigate the stability of the catalysts.All the measurement results provide strong evidence that 1 demonstrates oxidative and hydrolytic stability for the photocatalytic water oxidation process.2.A metal-organic framework Co-MOF-74 was synthesised and invesgated as a water oxidation catalysts.We systematically investigated the variables of photocatalytic reaction,including pH,buffer types,and photosensitizers to obtain the optimal conditions.Multiple exeperiments including XRD,XPS,AAS were apply to systemically study the stability of the catalysts.All the results demonstrated Co-MOF-74 is efficient and highly stable.3.We synthsis and characterized a Co-based polyoxometalate Na7H10[Co6?H2O?2(PW9O34)2(PW6O26)]·30H2O.The catalyst concentration,pH,buffer types,and photosensitizers were studied to obtain the optimal conditions.Multiple exeperiments including FT-IR,UV-vis,catalyst aged experiments and DLS were applied to systematically study the stability of the catalysts.These results confirmed that Na7H10[Co6?H2O?2(PW9O34)2(PW6O26)]·30H2O is efficient and stable during the photocatalytic water oxidation process. |
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