Synergy of sp2-hybridized carbon doping and photogenerated surface oxygen vacancies for the enhanced photocatalytic performance of BiOCl and solvent effects

Abstract

It is an urgent task to develop highly efficient photocatalysts to achieve rapid treatment of water pollutants. Carbon doping, especially using sp² hybridized carbon, which has rarely been studied, can offer new adsorption sites and improve light utilization. In this work, a series of predominantly sp² hybridized carbon-doped BiOCl photocatalysts were constructed in three different solvents via a one-step solvothermal method, and carbon doping sites are discussed in detail. The influence of solvents (ethylene glycol, ethanol and water) on the growth, physicochemical properties and application performance of BiOCl was examined, and a possible formation mechanism is put forward based on systematic characterization. Moreover, sp² carbon doping was found to be involved in enhancing light utilization, offering new adsorption sites and accelerating hole transport. The catalyst generates light-induced surface oxygen vacancies during the photocatalysis process, which promotes the separation of carriers and O₂ activation, demonstrating a synergistic effect with sp² carbon doping. The optimized catalyst exhibits a photodegradation efficiency of 100% for RhB within only 6 min, maintaining excellent stability and resistance to environmental factors. This work not only elucidates the role of sp² carbon doping in the photocatalytic ability of BiOCl, but also offers novel insights into dynamic defect engineering, presenting a practical strategy for designing adaptive photocatalytic systems.