Carbon- and oxygen-doped hexagonal boron nitride for degradation of organic pollutants

Carbon- and oxygen-doped hexagonal boron nitrides (BCNOs) with good chemical stability and photoresponsiveness to visible light are found to be promising metal-free catalysts for degradation of Rhodamine B (RhB). By doping with heteroatoms of carbon and oxygen, insulating hexagonal boron nitride was transformed into semiconducting BCNO. The BCNO photocatalyst presents photodegradation performance towards RhB, with degradation rates up to 1.39 h⁻¹ (0.05 wt% catalyst loading). The active species involved in the photoreaction were demonstrated to be superoxide anion radical (˙O₂ ⁻) and holes (h⁺), as opposed to ˙OH in the most studied titanium dioxide. The stability of BCNO in highly acidic environments was exploited for catalyst regeneration, as is necessary after long-term use and poisoning. This work demonstrates that BCNO is a promising low-cost and metal-free photocatalyst for environmental pollution remediation.