Photoelectrocatalytic Reduction of CO ₂ over CuBi ₂ O ₄ /TiO ₂ ‐NTs under Simulated Solar Irradiation

Abstract

Abstract The present study focused on the photoelectrocatalytic reduction of CO 2 on CuBi 2 O 4 /TiO 2 ‐NTs(TiO 2 nanotube arrays)catalyst under simulated solar irradiation. CuBi 2 O 4 was successfully loaded on TiO 2 ‐NTs via pulse deposition regime from a nitric acid aqueous solution with Bi 3+ /Cu 2+ molar ratio of 2, followed by calcination in air at 450 °C. A series of condition experiments were conducted to obtain excellent‐performance CuBi 2 O 4 film. The crystalline structure, morphology and elemental composition of catalysts were characterized by X‐ray diffractometer(XRD), field‐emission scanning electron microscope (FE‐SEM) and energy dispersive spectroscopy (EDS). Light absorption characteristics were analyzed by ultraviolet‐visible spectrophotometer (UV‐Vis). Experimental results show that the coupling of CuBi 2 O 4 and TiO 2 ‐NTs leads to a better visible light response and photoelectrocatalytic performance for CO 2 reduction. The photocurrent on CuBi 2 O 4 /TiO 2 ‐NTs electrode increases significantly compared with that on TiO 2 ‐NTs. Under optimized experimental condition, the photocurrent is up to 0.5 mA cm −2 at potential of −0.5 V vs. SCE. The liquid products determined by Gas Chromatograph are mainly composed of ethanol with minor formaldehyde.