Oxygen vacancy-boosted 0D/2D BiOBr/g-C3N4 heterojunctions for efficient visible-light photocatalytic removal of 1-naphthoic acid

Nowadays, industrial wastewater contains abundant refractory organic pollutants, which seriously threaten ecological environment and human health. As an eco-friendly and efficient technology, photocatalysis is a promising approach for wastewater purification. Nevertheless, the rapid recombination of photogenerated carriers greatly limits the practical application of conventional photocatalysts. Introducing oxygen vacancies (OVs) into photocatalysts is an effective strategy to solve this problem and improve photocatalytic activity. In this study, we facilely synthesized 0D/2D BiOBr-OVs/g-C 3 N 4 heterojunction by a one-pot solvothermal method, which was composed of zero-dimensional (0D) oxygen vacancy BiOBr-OVs and two-dimensional (2D) g-C 3 N 4 components. The 0D/2D heterojunction exhibited enhanced visible-light degradation for the hazardous pollutant 1-naphthoic acid. And its removal rate by 0D/2D composites was up to 76.3% after 100 min of irradiation, which was 1.61 and 1.45 times those of 2D g-C 3 N 4 and 0D BiOBr-OVs. The noticeably increased removal efficiency of 0D/2D composites for 1-naphthoic acid was attributed to the rational utilization of oxygen vacancies to promote charge carrier separation. And the tight bonding between components also contributed to photoinduced carrier migration and exerted a synergistic effect for photocatalysis. Possible degradation pathways were proposed for the intermediates via gas chromatography-mass spectrometry (GC-MS) qualitative analysis, and their toxicity was evaluated using the Toxicity Estimation Software Tool (T.E.S.T.). This paper provides an innovative approach for one-step manufacture of 0D/2D nanojunctions with oxygen vacancies, and advances to prospective organic photodegradation applications.