Photoelectrode using metal nitride as conductive substrate and preparation method thereof

Abstract

The invention discloses a photoelectrode and a preparation method thereof. A metal nitride substrate serves as a current collection body and is tightly contacted with a photoactive layer which is a non-complete oxide semiconductor with or without the decoration of a promoter, so that the photoelectrochemical photoelectrode is formed. The preparation method comprises the following steps of: firstly, preparing the conductive metal nitride substrate, wherein the lowest sheet resistance of the conductive metal nitride substrate is 1.8 ohm per square, the electrical resistivity is 0.16 mohm per centimeter, the conductive metal nitride substrate is superior to commercial FTO and ITO; and secondarily, depositing or coating the semiconductor or a precursor containing a semiconductor metal constituent, performing high-temperature processing in an inert atmosphere or a hydride atmosphere of the semiconductor nonmetal constituent. The metal nitride substrate can keep conductivity after being subjected to high-temperature processing in the inert or hydride atmosphere (such as to 900 DEG C in ammonia gas), and is applicable for high-temperature preparation process of a non-all oxide semiconductor photoelectrode, and the whole photoelectrode preparation process is easy to industrialize. The photoelectrode can be used for application such as water decomposition, hydrogen preparation and carbon dioxide conversion by means of solar energy in photoelectrochemistry.

Description

technical field [0001] The invention relates to a structure of a photoelectrode for photoelectrochemical process in solar energy utilization and a preparation method thereof. Background technique [0002] With the increasingly prominent energy problems, solar energy, as an abundant clean energy, has been paid more and more attention to the research on its utilization. As an important means of converting and utilizing solar energy, photoelectrochemistry has also made good progress in its research. Fujishima and Honda first reported metal In-connected single crystal TiO 2 The photoelectrode realizes photoelectrochemical water splitting (Nature1972, 238, 37.), which is the first of its kind in the study of photoelectrochemical conversion of light energy. Then many oxide semiconductor materials were developed as photoactive layers, such as WO 3 (Chemical Communications2012, 48, 729-731), ZnO (Adv. Funct. Mater. 2009, 19, 1849-1856), In 2 o 3 (Electrochimica Acta 2000, 45, 1...

AI Technical Summary

Problems solved by technology

Wide bandgap oxide semiconductors such as TiO 2 、WO 3 The photoresponse range is small, and sunlight cannot be fully utilized; and narrow-bandgap all-oxide semiconductors often have one or more of the following problems: (1) The position of the conduction band is too low, resulting in insufficient electron reduction, and a large bias is required (such as α -Fe 2 o 3 , BiVO 4 ); (2) The charge separation efficiency of non-full d electrons is not high (such as CaFe 2 o 4 , α-Fe 2 o 3 ); (2) unstable under photoelectrochemical reaction (such as Cu 2 o)

Literature (Adv.Mater.2013, 25, 125) reported that Ta 3 N 5 Photoelectrodes, in NH 3 Ta and Ta 3 N 5 Ta 2 N, but no proposal to adopt such as Ta 2 Nitrides such as N are used as conductive substrates, and semiconductors are not deposited on metallic nitride substrates.

Moreover, the abundance of tantalum in the earth's crust is only 2ppm, and the cost of metal tantalum or tantalum nitride as a conductive substrate is high

Images