Interfacial engineering of CdMnS/gC₃N₄@rGO heterostructure for visible light-driven photocatalytic degradation of ciprofloxacin

Improving light absorption ability and prolonging the life-time of charge carriers through interfacial bonding are considered to be an effective approach to developing advanced photocatalysts. This study describes the synthesis of CdMnS-gC₃N₄/rGO (CMS-gCN/rGO) composite with an interfacial Cd-N-bond, using hydrothermal method. An excellent performance is measured, attaining the degradation efficiency of 98 % for ciprofloxacin in 60 min of irradiation time. The efficiency value surpasses that of CMS and gCN by 2.6 and 2.3 times, respectively. Such an improvement originates from the interfacial coupling between CMS and gCN and the subsequent composite formation with rGO, facilitating the separation of charge carriers. The charge transfer mechanism is corroborated by the combined time-resolved photoluminescence (TR-PL) and radicals trapping experimental findings. The toxicity assays against E. coli confirmed no inhibition of bacterial growth in the presence of CMS-gCN/rGO, affirming its environmentally benign nature. This study provides a new perspective for the development of an interfacial connected heterostructure and its composite with graphene for the photocatalytic removal of organic pollutants.