Co-sensitization of mesoporous ZnS with CdS and polyaniline for efficient photocatalytic degradation of anionic and cationic dyes

Abstract

Toxic pollutants such as organic dyes are released from different industries and discharged into water sources leading to a serious health problem. Herein, mesoporous ZnS with large surface area (207.4 m2/g) synthesized by a new and simple surfactant free method at room temperature. Next, ZnS modified with CdS to get a series of ZnS/CdS binary hybrids (ZC1, ZC2, ZC3 and ZC4). After that, various amounts of polyaniline (PANI) were added to produce a series of ZnS/CdS/PANI ternary composites (ZC2P1, ZC2P2, ZC2P3, and ZC2P4) for the first time. The sensitization with PANI led to an increase in surface area and pore diameter. The degradation percentage of ZnS, ZC2, and ZC2P3 is 54.7%, 81.1%, and 96.5%, respectively. The degradation rate constant of 20 mg/L RhB in presence ZnS, ZC2 and ZC2P3 is 0.5 × 10−2, 0.91 × 10−2, and 1.7 × 10−2 min−1, respectively. A possible mechanism for the enhanced photocatalytic activity is proposed.