Delafossite CuGaO₂ as promising visible-light-driven photocatalyst: synthesize, properties, and performances

Abstract

3R-delafossite CuGaO2 sample with high crystallinity and single phase was prepared by simple low-temperature hydrothermal method. The fundamental physicochemical properties of 3R-delafossite CuGaO2 were systematically studied by density functional theory calculations and experimental characterization. Through a series of characterization, analysis, (photo)electrochemical and photocatalytic activity testing, the as-prepared CuGaO2 samples exhibit the potential for hydrogen production and high photocatalytic degradation for tetracycline hydrochloride (TCH). Furthermore, CuGaO2 photoelectrode exhibits long-term stability and large photocurrent density. These observations suggest that 3R-delafossite CuGaO2 is a potential promising photocatalyst driven by visible-light. Finally, possible breakthrough directions of 3R-delafossite CuGaO2 photocatalyst are discussed.

Copper Oxide-Based Photocatalysts and Photocathodes: Fundamentals and Recent Advances

“…Delafossites are an example of ternary oxides, which have a quasi-two-dimensional layered superlattice structure. In this structure, the linear O–A–O dumbbell layers and oblique BO 6 octahedra layers are alternately arranged [ 154 ]. Delafossite materials based on copper (CuMO 2 ; where M = Fe, Rh, Cr, Al, Ga) has attracted great attention as a possible cathodic photomaterials for solar fuel production because of the small band gap energy, high onset potential and good stability in aqueous electrolytes.…”

“…70% at +0.3 V, which can be significantly improved by the addition of sacrificial hole scavengers. A hydrothermal method has been applied also to prepare CuGaO 2 [ 154 ]. The CuGaO 2 electrode exhibits the potential for hydrogen production, long-term stability and large photocurrent density in PEC tests.…”

Identification of a Fe-Dependent Optical Mode in CuAl1–xFexO2

“…Ideally, they should be simple to synthesize and have a good surface-to-volume ratio. Metal oxides such as delafossite (ABO 2 ) crystals have attracted attention because of their chemical stability during electrolysis − and a tendency for native p-type doping and often with small indirect gaps ( E g < 1.5 eV) which makes them into good conducting electrodes. − Delafossite crystals, such as CuAlO 2 , have wide indirect and direct optical band gaps ( E g ′ = 3.0 and 3.8 eV, respectively), exhibit a large exciton binding energy, and have strong lattice polarization. − Moreover, in the powdered form, there are surface states that add to the optical spectra without necessarily offering useful charges for photocatalysis . The optical absorption needs to be increased in the visible/solar range of the electromagnetic spectrum specifically to improve photocatalytic activity.…”

Experimental and Computational Exploration of the Dilute Magnetic Delafossite CuAl1-xFexO2 Alloys

“…A potential photocatalyst should have high quantum-efficiency, be chemically stable in an aqueous environment, be durable, have a simple synthetic process, and be easy for mass production. Oxide families have attracted particular attention thanks to their chemical stability in electrolytes [18][19][20][21][22][23][24][25][26]. However, mostly they are transparent to the solar spectrum and consequently of little practical use.…”

“…However, mostly they are transparent to the solar spectrum and consequently of little practical use. Delafossite family (AMO2) has been one of the candidates, and a lot of studies have been done on them in recent years because of their outstanding longevity, elements abundance, much lower cost, and better absorbance in the solar spectrum range [21][22][23][24][26][27][28][29][30][31][32][33]. However, to date, a limited number of delafossite have been reported capable of carrying out photoelectrocatalysis, including CuAlO2, CuLaO2, CuCrO2, CuYO2, CuFeO2, and CuRhO2 [31].…”