. 2020 Jan 24;4(3):1900087. doi: 10.1002/gch2.201900087

Table 2.

Comparison of photocurrents for CuO‐based electrode

Photocathode material	Synthesis process	Photocurrent	Thickness	Refs.
CuO thin film	Sputter	−0.65 mA cm⁻² @ −0.45 V (Ag/AgCl)	≈500 nm	12
NiO‐CuO thin film	Sol–gel	−1.07 mA cm⁻² @ −0.55 V (Ag/AgCl)	850 nm	17
CuO thin film	RF‐magnetron sputtering	−3.1 mA cm⁻² @ 0 V (RHE)	500 nm	38
Au‐Pd‐decorated CuO thin film	RF‐magnetron sputtering	−3.88 mA cm⁻² @ 0 V (RHE)	500 nm	38
CuO thin film	Sol−gel process	−0.55 mA cm⁻² @ 0.05 V (RHE)	600 nm	51
CuO thin film	Electrolysis deposition‐thermal oxidation	−1.8 mA cm⁻² @ 0 V (RHE)	not provided	52
Li‐doped CuO nanoparticles	Flame spray pyrolysis	−1.7 mA cm⁻² @ −0.55 V (Ag/AgCl)	1700 nm	53
CuO nanoparticles films	Solution process	−1.2 mA cm⁻² @ −0.55 V (Ag/AgCl)	1340 nm	54
CuO thin film	Sol–gel method	−0.7 mA cm⁻² at 0 V versus RHE	≈500 nm	This work
CuO thin film with TiO₂ protecting layer (CuO‐TiO₂)	Sol–gel method	−1.3 mA cm⁻² at 0 V versus RHE	≈500 nm	This work
CuO thin film with TiO₂ protecting layer and Au‐Pd co‐catalyst nanostructures (CuO‐TiO₂‐AuPd)	Sol–gel method and RF sputtering	−1.9 mA cm⁻² at 0 V versus RHE	≈500 nm	This work
–COOH‐functionalized graphene into the CuO film (CuO:G‐COOH)	Sol–gel method	−1.32 mA cm⁻² at 0 V versus RHE	≈500 nm	This work
–COOH‐functionalized graphene into the CuO film (CuO:G‐COOH) with TiO₂ protecting layer (CuO:G‐COOH)‐TiO₂	Sol–gel method	−1.75 mA cm⁻² at 0 V versus RHE	≈500 nm	This work
–COOH‐functionalized graphene into the CuO film (CuO:G‐COOH) with TiO₂ protecting layer and Au‐Pd co‐catalyst nanostructures (CuO:G‐COOH)‐TiO₂‐AuPd	Sol–gel method and RF sputtering	−2.5 mA cm⁻² at 0 V versus RHE	≈500 nm	This Work