Method for preparing hydrogen through photoanode-photovoltaic battery coupled dual-illumination fully-photic-driven decomposition of water

Abstract

The invention relates to a method for preparing hydrogen through photoanode-photovoltaic battery coupled dual-illumination fully-photic-driven decomposition of water. Efficient decomposition of water is realized under sunlight illumination conditions by using coupling of a photoelectrocatalysis technology with a photovoltaic battery technology, adopting a water oxidation cocatalsyt modified semiconductor material as a photoanode, placing a proton reduction cocatalyst modified Si battery in an electrolyte as a photocathode, directly connecting the positive electrode of the Si battery with the anode through a lead and allowing the surface of the cathode to contact with the electrolyte. The method realizes fully photic driven decomposition of water without applied bias conditions, and the solar energy utilization efficiency STH of the method reaches 2.2% or above.

Description

1. Technical field [0001] The invention relates to a photoanode-photovoltaic cell coupled double-irradiation complete light-driven method for decomposing water to produce hydrogen. Specifically, the construction of a two-electrode form light-driven water splitting system including semiconductor photoanode and Si cell photocathode coupling and the corresponding BiVO 4 Preparation and modification method of photoanode, modification treatment method of Si battery photocathode. 2. Background technology [0002] Energy and environmental issues are two major issues facing the survival and sustainable development of human society. Using solar energy to produce clean and high-combustion hydrogen energy is a potential ideal way to solve these two problems. The most common and effective way of solar-chemical energy conversion is to use the photogenerated holes and electrons generated by semiconductors to absorb light energy to be used for water oxidation and reduction half-reactions...

AI Technical Summary

Problems solved by technology

[0003] The photocatalytic water splitting technology of the powder system has been developed for decades. At present, there are not many systems that can achieve water splitting under visible light. At present, the two systems with the highest quantum efficiency of visible light catalytic water splitting include Rh-Cr reported by the Domen group. 2 o 3-x / GaN:ZnO catalyst quantum efficiency 5.2% at 400nm wavelength and Pt / ZrO 2 / TaON-Pt / WO 3 The quantum efficiency of the Z-Schem system at 420nm wavelength is 6.3% (Nature, 2006, 440, 295. and J.Am.Chem.Soc.2010, 132, 5858.), according to the corresponding solar energy utilization efficiency is less than 1%;

The addition of an external bias voltage can significantly promote the separation of carriers and increase the photocurrent, but it also consumes electrical energy, so the solar energy utilization efficiency of the photocatalytic water splitting system is relatively low. The highest solar energy utilization efficiency reported in the literature is less than 2 %

However, the research of directly adding photovoltaic cells to the external circuit of the photolytic cell is similar to the photovoltaic cell power generation coupling electrolysis technology. The device consists of two parts, which are relatively complicated, and involve the packaging of solar cells and the connection and matching between the two. question

[0010] E.L.Miller et al. (International Journal of Hydrogen Energy, 2003, 28, 615-623.) deposit a layer of WO on the positive side of multi-junction solid silicon cells and GIS photovoltaic cells 3 or Fe 2 o 3 , a hydrogen-desorption catalyst is deposited on the negative electrode side, and a monolithic composite multi-node structure photoelectrode is constructed; where WO 3 Combined with a 1.5V dual-cell battery, the estimated maximum STH is 3.1%, mainly limited by WO 3 Absorption range is too narrow; Fe 2 o 3 Combined with three batteries above 1.85V, the corresponding limit STH is 9.2%, but Fe 2 o 3 The current of the layer must match the current of each of the three batteries, which is very difficult to achieve

Alex Stavrides et al. (Proc.of SPIE, 2006, 6340, 63400K) utilize polysilicon cell, deposit a layer of WO on it 3 , constitute stainless steel / ni2pnilp / ZnO / WO 3 The composite structure of SiC:H and Si battery monolithic composite structure (a-Si / a-Si or a-Si / nc-Si) / a-SiC:H(p) / a-SiC:H(i), and according to the intersection point of the I-V curve of the Si battery and the I-V curve of the photoanode material three-electrode system, the operating point of the device Analysis was performed and it was predicted that STH could reach 3% and 10%, respectively, but this prediction using the I-V curve of the three-electrode system was inaccurate

Moreover, although the composite photoelectrode with monolithic structure can effectively increase the light absorption, its overall efficiency is still limited by the photoelectric properties of semiconductor materials, WO 3 or Fe 2 o 3 The position of the conduction band should be more than 0.4V negative to the potential of the hydrogen-producing electrode, plus the overpotential of oxygen release, so the external voltage is relatively large, and multiple batteries are required, and the corresponding preparation process of the entire device requires higher requirements.

In addition, this monolithic photoelectrode can produce H 2 Produced on the back 2 , although the two are separated, it is difficult to achieve H in practical applications 2 / O 2 gas separation

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