Rapid One-Pot Synthesis and Photoelectrochemical Properties of Copper Vanadates

Solution combustion synthesis (SCS) is shown to be versatile for the rapid-one-pot synthesis of three compounds and four polymorphs in the Cu–V–O ternary family: α-CuV2O6, α- and β-Cu2V2O7, and γ-Cu3V2O8. These compounds feature copper/vanadium stoichiometric ratios ranging from 1:1 to 3:1; their structural, electronic, optoelectronic, and photoelectrochemical attributes were comprehensively characterized by a combination of theoretical and experimental techniques. The main contribution of the present study is the demonstration that a range of stoichiometries in this compound family can be derived simply by tuning the precursor mole ratio in the SCS procedure. The Cu–V–O family of samples, derived by SCS, is shown to exemplify the strong effect of compound stoichiometry on the optoelectronic and photoelectrochemical properties. Overall, α-CuV2O6 showed the best performance, rooted in the direct nature of the optical transition in this material. Finally, SCS is very time-efficient and the various compositions can be obtained in a matter of minutes, as opposed to hours or even days in classical solution-based or ceramic synthesis routes.