Nanostructure Metal Sulfides for Photocatalytic Water Remediation

Water is an essential commodity for civilization, and, without it, life cannot run. Many anthropogenic activities generate wastewater of different types. Thus, the treatment of wastewater to supply reusable water becomes necessary. In this context, development of efficient, cost-effective water remediation technology is an urgent need. Photocatalytic degradation of organic (dyes, synthetic pesticides, etc.) and inorganic (heavy metals, ions, etc.) pollutants is an emerging sustainable technology to treat wastewater emitting from different sources. Solar-assisted photocatalysis with suitable photocatalysts made the photocatalytic water remediation more attractive. The semiconductor photocatalysts play a key role in this remediation process. In past decades, numerous inorganic and organic semiconductors and their composites have been developed for these purposes. Among inorganic semiconductors, metal sulfides are considered to be the most potential candidate for their intriguing physiochemical properties. The efficiency of the photocatalytic waste treatment relies exclusively on the photon capture and their effective utilization. Tailoring of the optoelectronic and textural properties can boost the degradation capacity of the photocatalyst. In this aspect, development of nanostructure metal sulfide photocatalysts comes into the limelight. The photoreactivity and catalytic efficiency can be tuned by exploring the shape, size, and crystal structure of nanostructure metal sulfides. Development of heterostructure metal sulfides also found to be a noteworthy protocol. Moreover, the design of a suitable catalytic system for practical application is very essential. In the present chapter, the fundamental principle of the metal sulfide–based photocatalysis, the design of solar active metal sulfides, and the insights on the physiochemical activity tailoring of a catalyst have been discussed thoroughly. In addition, the practical application of photocatalyst in wastewater treatment is discussed. Further, this chapter also included basic information on the photo-catalytic mechanism and development of photocatalytic systems to the broad readership.