Review of Recent Developments in the Fabrication of ZnO/CdS Heterostructure Photocatalysts for Degradation of Organic Pollutants and Hydrogen Production

Abstract

Researchers have recently paid a lot of attention to semiconductor photocatalysts, especially ZnO-based heterostructures. Due to its availability, robustness, and biocompatibility, ZnO is a widely researched material in the fields of photocatalysis and energy storage. It is also environmentally beneficial. However, the wide bandgap energy and quick recombination of the photoinduced electron–hole pairs of ZnO limit its practical utility. To address these issues, many techniques have been used, such as the doping of metal ions and the creation of binary or ternary composites. Recent studies showed that ZnO/CdS heterostructures outperformed bare ZnO and CdS nanostructures in terms of photocatalytic performance when exposed to visible light. This review largely concentrated on the ZnO/CdS heterostructure production process and its possible applications including the degradation of organic pollutants and hydrogen evaluation. The importance of synthesis techniques such as bandgap engineering and controlled morphology was highlighted. In addition, the prospective uses of ZnO/CdS heterostructures in the realm of photocatalysis and the conceivable photodegradation mechanism were examined. Lastly, ZnO/CdS heterostructures’ challenges and prospects for the future have been discussed.

Development of stable S-scheme 2D–2D g-C3N4/CdS nanoheterojunction arrays for enhanced visible light photomineralisation of nitrophenol priority water pollutants

“…Literature has widely examined this phenomenon, and it is well established that the photo-corrosion of CdS results from the interaction between the semiconductor and the surrounding environment, such as the presence of oxygen or water molecules. There have been several research on this topic to investigate the mechanisms of photo-corrosion and to develop methods to mitigate its detrimental effects, including the use of protective coatings or the modification of the semiconductor surface chemistry 31 – 35 . These investigations have brought to light how crucial it is to thoroughly know and regulate the behavior of CdS-based devices in order to appreciate the intricate interaction between semiconductor characteristics and their surroundings.…”

“…The integration of an additional semiconductor material to create a heterojunction has been reported to be a viable approach to address the limitations inherent in CdS-based photocatalysts 35 – 37 . A fortuitous discovery reveals that the alignment of the valence and conduction bands of graphitic carbon nitride (g-C 3 N 4 ) and cadmium sulfide (CdS) exhibits a highly compatible overlap of band energies, rendering them eminently suitable for the construction of heterostructures 38 , 39 .…”

Synthesis of Novel Nanocomposite CaO/AC/ZnO from Biogenic Wastes of Date Palm Seeds from The Najran Region (Saudi Arabia) and Eggshells for Degradation of Methylene Blue

“…•OH can be formed by oxidants like hydrogen peroxide and ozone. This can be finished using homogeneous or heterogeneous photocatalysts such as ZnO [20], or with energy resources like heat, ultrasounds, and ultraviolet light [21]. The heterogeneous photocatalytic method effectively breaks down toxic substances in the environment by producing excitons when exposed to light [22] [23].…”

CdS Nanoparticles Supported by Cobalt@Carbon-Derived MOFs for the Improved Adsorption and Photodegradation of Ciprofloxacin

“…However, CdS alone are prone to the insufficient separation of photogenerated charge carriers, particle aggregation, and photocorrosion, which seriously restrict their activity as well as practical applications on a large scale [2]. In order to overcome the inherent defects of a single material, various efforts have been made to modify the structure and composition of CdS [3][4][5]. Among these strategies, coupling CdS with carbon-based materials has been proven to be effective and economical in improving photocatalytic efficiency.…”