Green derived metal sulphides as photocatalysts for waste water treatment. A review
S. Munyai, Nomso C. Hintsho‐Mbita
Abstract
The wastewater discharged from the textile industry consists of a large amount of colored materials referred to as dyes. The management of these dyes is very poor and they have an effect on the aquatic life and the surrounding environment. Several methods have been used to treat these dyes but were found to have a lot of limitations. The Advanced Oxidation Processes (AOPs) through photocatalysis has been a more preferred method thus far. For these dyes to be treated via photocatalysis, an efficient photocatalyts needs to be developed. In the past, the synthesis of photocatalyst like metal sulphides were done using chemical methods which were found to use toxic reagents, required high temperature and pressure, hence significant efforts have been made to produce cleaner and safer materials. In this review, we discuss the conventional and green synthesis of metal sulphides with an extra emphasis on Zinc Sulphide (ZnS) and Cadmium Sulphide (CdS) using plants, fungi and bacteria. We focus on their use as photocatalysts for the degradation of dyes. Lastly, the challenges of these green derived metal sulphides and their possible future perspectives are highlighted.