Preparation of a coated ZH-scheme (SnS2@CdS)/TiO2(0 0 1) photocatalyst for phenol degradation with simultaneous Cr(VI) conversion

The construction of highly efficient and multifunctional composite photocatalysts has attracted extensive attention in the field of environmental governance. In this study, an efficient coated ZH-scheme (SnS2@CdS)/TiO2(0 0 1) photocatalyst is resoundingly prepared by hydrothermal, isoelectric point and continuous ion layer adsorption reaction methods and a sequence of characterizations are carried out. The photocatalytic activity of (SnS2@CdS)/TiO2(0 0 1) photocatalyst is evaluated via degradation of phenol with simultaneous conversion of Cr(VI) under sunlight irradiation. Furthermore, the effects of initial concentrations of phenol and Cr(VI), variety of photocatalyst, solution pH, (SnS2@CdS)/TiO2(0 0 1) photocatalyst dosage and recycling times on phenol degradation and Cr(VI) conversion are investigated. The crucial active species of phenol degradation are explored by capture experiments. When the coated ZH-scheme (SnS2@CdS)/TiO2(0 0 1) photocatalyst dosage is 1.0 g/L, phenol and Cr(VI) concentrations are 20 mg/L and 40 mg/L, respectively and solution pH is 4.0, the phenol degradation rate and the Cr(VI) conversion rate could reach 85.52 % and 95.69 %, respectively. Additionally, the possible photocatalytic mechanism of phenol degradation with synchronous Cr(VI) conversion caused by (SnS2@CdS)/TiO2(0 0 1) photocatalyst is proposed. It can be hoped that this work will provide a feasible way to treat high concentrations of organic pollutants and simultaneously convert heavy metal ions.