Metal-organic frameworks derived Bi2O2CO3/porous carbon nitride: A nanosized Z-scheme systems with enhanced photocatalytic activity

A bismuth-based metal-organic frameworks (MOFs) derived strategy is developed to construct nanoscale Bi2O2CO3/porous g-C3N4 Z-scheme heterojunction. Bi2O2CO3 nanoparticles uniformly distribute in the surface, edge and interlayer of g-C3N4 nanosheets, thus significantly increasing intimate contact at the interface. Furthermore, the Z-scheme heterojunctions and doped N atoms escaping from g-C3N4 to Bi2O2CO3 provide a charge transport chain to promote the charge carriers separation and accelerate the oxidation of O2− by holes, as confirmed by photoluminescence, photoelectrochemical and electron spin resonance measurements. Benefitting from these, the optimized composites not only outperform the pristine g-C3N4 in the removal of sulfamethazine (SMT) within 90 min visible light illumination (λ > 420 nm) but also serve to selectively generate singlet oxygen (1O2) during the molecular oxygen activation. The present study provides some guidelines for the design of photocatalysts via a MOF-assisted route toward sustainable environmental remediation.