Enhanced Photocatalytic Activity of Nickel(II)-Doped Bi2O2CO3 Nanosheets for Efficient Nitric Oxide Removal

Abstract

Bi₂O₂CO₃ is a typical bismuth-based semiconductor photocatalyst that has attracted much attention because of layered structure and polarization characteristics. However, the wide bandgap of Bi₂O₂CO₃ limits its practical applications in photocatalysis. In this study, the nickel (II)-doped Bi₂O₂CO₃ (Ni²⁺-Bi₂O₂CO₃) with oxygen vacancies was prepared by adding a controllable amount of nickel ions. The photocatalytic efficiency of the optimized sample for ppb-grade NO under visible light irradiation is 59.4 %, which is 2.8 times than that of its counterpart, Bi₂O₂CO₃ (21.2 %). Based on experiments and characterizations, Introduction of nickel ions and oxygen vacancies improves the photocatalytic performance of Ni²⁺-Bi₂O₂CO₃, which not only lowered the bandgap from 3.25 eV to 2.92 eV, but also reduced the recombination of photogenerated carriers by formation of the impurity level. Furthermore, the adsorption and photocatalytic conversion pathway of NO was explored by in situ DRIFTS, the principal byproducts of photocatalytic oxidation of NO are NO₃⁻ and NO₂⁻. This work offers a new perspective to improve the photocatalytic activity by doping mothed for air purification.