Large-scale solar water decomposition hydrogen production method based on photocatalysis - photoelectrocatalysis

Abstract

The invention provides a high-efficiency large-scale solar water decomposition hydrogen production technique based on photocatalysis - photoelectrocatalysis. The technique comprises the following steps that soluble high-valence electron carriers are converted into low-valence electron carriers by a powdered photocatalyst under illumination of the sun, so that large-area solar storage is realized, besides, oxygen is emitted, and protons are generated; an electrolyte solution storing the electron carriers and the protons is conveyed into a photoelectrocatalysis basin; and a photon-generated carrier is generated at the anode of the photoelectrocatalysis basin by utilizing the sunlight, so that the low-valence electron carriers are oxidized into the high-valence electron carriers, and protons are combined at the cathode of the photoelectrocatalysis basin to generate hydrogen. After the hydrogen is collected, the electrolyte solution is returned to a photocatalysis system for recycling. The whole reaction is driven by sunlight to realize the conversion of solar energy into hydrogen energy.

Description

technical field [0001] The invention relates to the technical field of photochemical conversion of solar energy to produce solar fuel, in particular to a technology for realizing large-scale solar water splitting hydrogen production through a coupling system of photocatalysis and photoelectric catalysis. Background technique [0002] As a clean energy, hydrogen has the advantages of high combustion value and zero pollution emission, and is often used as a hydrogen source for fuel cells and hydrogen-powered vehicles. At the same time, it is also a commonly used industrial raw material, widely used in synthetic ammonia, petroleum hydrocracking, and metallurgical industries. At present, the production of hydrogen mostly relies on catalytic reforming reactions based on fossil resources (such as: C+2H 2 O→2H 2 +CO 2 ), it can be seen that every ton of H produced 2 , needs to consume 3 tons of coal and generate 11 tons of CO 2 , Such a high carbon emission will undoubtedly ha...

AI Technical Summary

Problems solved by technology

Among them, the process equipment of the powder photocatalyst system is simple but the efficiency is very low, and the generated hydrogen and oxygen are mixed together, which will bring great safety hazards in future applications. H 2 with O 2 The problem of separation is a big challenge

However, this patent needs to provide additional electric energy input, and the required bias voltage is above 0.85V; and the photocatalyst (WO 3 、TiO 2 , SrTiO 3 etc.) The light absorption range is concentrated in the ultraviolet part, and the WO with the widest light absorption range 3 The utilization of the solar spectrum by the catalyst is also very limited, it can only absorb sunlight below 470nm, and the number of photons below 470nm in the solar spectrum is only 3%; WO 3 The highest apparent quantum efficiency reported at present is only 31% (RSC Adv., 2014, 4, 8308-8316), and the conversion efficiency of solar energy to hydrogen energy in the photocatalytic-electrolytic coupling system is less than 0.5%.

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