Regulating the electronic structure of BiOBr by Cu-doping to promote efficient photocatalytic nitrogen fixation reaction

Abstract

Element doping is critical in regulating the electronic structure to enhance N₂ adsorption, opening up new possibilities for achieving highly efficient photocatalytic nitrogen reduction reactions (pNRR). In this study, we successfully prepared Cu-doped BiOBr (Cu-BiOBr) using a simple solvothermal method. Density Functional Theory (DFT) calculations and experimental investigations were employed to explore how Cu doping influences the performance of pNRR over BiOBr. The DFT analysis indicates that Cu doping alters the electronic structure, lowers the energy barrier of the reaction, and narrows the bandgap. This electronic structure adjustment leads to the remarkable NH₃ production rate of 466.3 μmol⋅g_cat⁻¹⋅h⁻¹ without the need for sacrificial agents in the 2 % Cu-BiOBr sample. In addition, based on the findings of DFT and in-situ FTIR, a detailed mechanism for the adsorption/activation and hydrogenation reaction of N ≡ N bonds on Cu-BiOBr was proposed. This research introduces a prospective way for designing transition metal-doped BiOBr catalysts with regulated electronic structures for pNNR, which has significant implications for advancing other material systems.