Ultrathin graphitic carbon nitride modified PbBiO2Cl microspheres with accelerating interfacial charge transfer for the photodegradation of organic contaminants

A novel sphere-like g-C3N4/PbBiO2Cl 2D-3D composite photocatalyst was fabricated via a reactive ionic liquid 1-hexadecyl-3-methylimidazolium chlorine ([C(16)mim]Cl) assisted one-pot solvothermal method. [C(16)mim]Cl could act as Cl source, dispersing and template agent in the meantime, which ensured the construction of PbBiO2Cl porous microspheres and high dispersity of ultrathin g-C3N4. Various techniques were adopted to investigate the morphology, structure, optical and electrochemical properties of the obtained catalysts. It could be observed that ultrathin g-C3N4 was dispersed evenly around PbBiO2Cl microspheres. The colorless contaminants including bisphenol A (BPA), ciprofloxacin (CIP) and colored rhodamine B (RhB) were selected as the model pollutants to appraise the photocatalytic performance of the as-prepared samples. Compared with single PbBiO2Cl, the composites presented obviously enhanced photocatalytic performance under the irradiation of visible light, and the optimum mass ratio of g-C3N4 was around 3 wt%. The improvement of photocatalytic activity could be ascribed to the tight interfacial contact between the two components that could promote the separation and transfer of photogenerated electron-hole pairs. Superoxide radical (O-center dot(2)-), holes and hydroxyl radical ((OH)-O-center dot) all participated in the photocatalytic reactions on account of radicals quenching experiments and electron spin resonance (ESR). This research extends the knowledge into the construction of other 2D-3D composite photocatalysts with preferable photocatalytic activities in the field of environmental remediation.