In Situ Construction of Porous β-Bi₂O₃/BiOCOOH Heterojunction Photocatalysts: Enhancing Nitrogen Fixation Activity by the Synergistic Effect of Oxygen Vacancies and Lattice Oxygen

Photocatalytic nitrogen fixation is considered as a multielectron reaction and a complex kinetic process, building high-performance nitrogen fixation photocatalysts to solve the activation of N2 and inhibit the recombination of photogenerated holes and electrons under the visible light condition. Herein, porous β-Bi2O3/BiOCOOH heterojunction photocatalysts with oxygen vacancies were prepared via BiOCOOH as a sacrificial precursor by the calcination method. The as-obtained β-Bi2O3/BiOCOOH catalyst with oxygen vacancies exhibited a high catalytic activity of about 65.56 μmol·g–1·h–1 for N2 fixation via deionized water as a solvent and methanol as a sacrificial agent. Both experimental and theoretical research indicated that the activity of β-Bi2O3/BiOCOOH heterojunction catalysts originated from the oxygen vacancies and lattice oxygen species. Compared to the single-component BiOCOOH structure, the porous β-Bi2O3/BiOCOOH heterojunction catalysts have achieved the absorption visible light range and have promoted the separation efficiency of charge carrier pairs by accommodating photogenerated electrons. Our findings afford a chance to improve a promising catalyst for photocatalytic nitrogen fixation.