Photoelectrode for producing hydrogen and oxygen by photoelectro-chemically decomposing water, preparation and application thereof

Abstract

A photoelectrode for producing hydrogen and oxygen by photoelectro-chemically decomposing water is characterized in that the photoelectrode is composed of a photocathode and a photoanode, wherein the photocathode and a photoanode are provide with quantum dots being assembled with assistance of a double-functional molecule. The invention achieves the establishment and the application of the photoelectrode for producing hydrogen and oxygen on the basis of semiconductors, quantum dots and catalysts. The photoelectrode is high in stability, is free of a sacrificial agent, is simple in operation, is good in repeatability, is strong in universality and is high in utilization rate on visible light. In addition, the catalyst is free of requirement of noble metals, is low in cost and is easy to obtain.

Description

technical field [0001] The invention relates to the field of photoelectric catalytic water splitting. More specifically, it relates to a photoelectrode based on p-type and n-type semiconductor substrates, quantum dots and catalysts for photoelectrochemical splitting of water to produce hydrogen and oxygen, and its preparation and application. Background technique [0002] With the rapid development of economy, human beings' demand for energy is increasing day by day. Fossil energy, as the most important energy consumed in the world today, has made outstanding contributions to the development of human industrialization. However, with the continuous exploitation of human beings, the depletion of fossil energy is inevitable. Relevant data show that most of the fossil energy will be exhausted within a few hundred years; on the other hand, the environmental problems accompanying the consumption of fossil energy have also received more and more attention from human beings. Ther...

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Problems solved by technology

In the absence of sacrificial reagents, quantum dots are used as photoanodic oxidation water, which has the problems of easy corrosion and poor stability, and the research progress in this area is relatively slow.

In 2010, Liu et al. (Angew.Chem.Int.Ed.2010,49,5966-5969) adsorbed CdTe quantum dots onto ZnO nanowires through thioglycolic acid to prepare a photoanode for water splitting, but their system did not Hydrogen and Oxygen are not really detected

But the problem with this kind of system is that CuGaSe 2 or CuInS 2 Semiconductors need to be prepared by atomic layer evaporation, which requires high equipment and complicated operations, and uses Pt as a catalyst, which is costly

In 2011, Sun Licheng et al. (Chem.Commun.2012, 48, 988-990) first connected organic dyes (P1) to NiO and used cobaloxime complexes as cocatalysts to construct the first case based on molecular photosensitizers and molecular Catalyst NiO photocathode, but the connection between the catalyst and NiO is weak, and it is easy to fall off from the electrode during operation, which affects the performance of the electrode

Organic dye molecules are commonly used sensitizers for NiO photocathodes, but the synthesis of organic dyes is complex, costly, and poor in stability

Professor Richard Eisenberg et al. (ACS Catalysis 2015, DOI: 10.1021 / cs5021035) chemically adsorbed CdSe quantum dots onto NiO, prepared CdSe / NiO electrodes, and carried out photoelectric hydrogen production reactions on cobalt or nickel complex hydrogen production catalysts, but this The obvious problem with the system is that it needs to be run in an electrolyte solution of organic solvent acetonitrile

In 2014, Liu et al. (ACS Nano 2014,8,10403-10413) made IrO X nH 2 O / CdS / TiO 2 The photoanode and the NiS / CdSe / NiO photocathode are connected in series to prepare a water splitting battery with double light absorbing layers, but the quantum dots are loaded by electrochemical deposition and chemical bath deposition respectively, so it is difficult to control the size of the quantum dots and the Loading and distribution on semiconductors

At the same time, the efficiency and stability of the system are poor without a passivation layer and a catalyst; in addition, the preparation of the system is cumbersome, and IrO X Catalysts are expensive

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