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Waste-derived materials obtained from the recovery and recycling of electronic waste (e-waste) such as batteries and printed circuit boards have attracted enormous attention from academia and industry in recent years, especially due to their eco-friendly nature and the massive increment in e-waste due to technological development. Several investigations in the literature have covered the advances achieved so far. Meanwhile, photocatalytic applications are especially of interest since they maintain mutual benefits and can be used for H2 production from solar water splitting based on semiconductor processing as a proper environmentally friendly technique for solar energy conversion. In addition, they can be utilized to degrade a variety of organic and non-organic contaminations. Nonetheless, to the best of the authors' knowledge, there has not been any comprehensive review that has specifically been focused on e-waste-derived photocatalytic materials. In this regard, the present work is dedicated to thoroughly discussing the related mechanisms, strategies, and methods, as well as the various possible photocatalysts synthesized from e-wastes with some critiques in this field. This brief overview can introduce modern technologies and promising possibilities for e-waste valorization, photocatalytic processes, and new photocatalytic degradation methods of eco-friendly nature. This paper discusses various e-waste-obtained photocatalytic materials, synthesis procedures, and applications, as well as several types of e-waste, derived materials such as TiO2, ZnO, indium tin oxide, and a variety of sulfide- and ferrite-based photocatalytic materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel visible driven WO 3 -CeO 2 heterojunction was successfully synthesized. • The prepared photocatalyst was applied for degradation of Sulfamerazine from an aqueous solution. • Incorporation of CeO 2 on WO 3 significantly enhanced the photodegradation percentage. • S-scheme mechanism was suggested for the boosted photocatalytic activity. • Photodegradation pathways of Sulfamerazine antibiotic were investigated. In this work, hierarchical WO 3 -CeO 2 hollow sphere heterojunctions were fabricated via a two-step hydrothermal method and applied for degradation of sulfamerazine antibiotic under visible light irradiation. The incorporation of CeO 2 into the WO 3 microspheres was confirmed by XRD, BET, HRTEM, and XPS analysis. The results revealed that the photocatalytic activity of WO 3 -CeO 2 heterojunction was greatly enhanced compared to pure CeO 2 and WO 3 samples, and the highest degradation percentage of sulfamerazine was achieved on the WO 3 -CeO 2 heterojunction with 30 mol. % CeO 2 content. This could be ascribed to the efficient separation of charge carriers which was facilitated by oxygen vacancies formed at the interfaces of two coupled semiconductors. EIS analysis verified that the charge transfer resistance of WO 3 -30CeO 2 heterojunction was decreased, which is due to the heterojunction effect. Moreover, based on the Mott-Schottky calculations, radical trapping experiments and ESR analysis, hydroxide radicals were identified as the main active species, and an S-scheme charge transfer mechanism was suggested to explain the enhanced photocatalytic activity. The possible degradation pathway of sulfamerazine was suggested through the detection of degradation intermediates by mass spectroscopy. [ABSTRACT FROM AUTHOR]

[Display omitted] • CuCo 2 S 4 was successfully embedded with S-scheme V 2 O 5 deposited on wrinkled g-C 3 N 4 lamella. • The ternary nanostructure demonstrated ultramost photocatalytic efficiency toward levofloxacin decomposition (98%). • Long-term reaction toward completed levofloxacin mineralization displayed the inconsequential quantity of released elements. • Consecutive cycling experiment suggested superb stability of nanocomposite. • Charge-flow relocation through the construction of interfacial electronic field was discussed. The influential light-harvesting and tremendous reduction capability along with the potentiality (photo)electrochemical merits of the thiospinels like CuCo 2 S 4 (CCS), appreciably bring forth an advancement in efficacious photocatalytic reactions. However, scant oxidation potential originated from 3p orbitals of sulfur atoms puts a damper on their performance and even is conducive to self-oxidation. In this research, the surfactant/template free of hierarchical yolk-shell-structured CCS thiospinels was synthesized using solvothermal sulfidation of the affordable glycerate-based CuCo-alkoxide. The as-synthezied CCS was successfully embedded with S-scheme V 2 O 5 deposited on wrinkled g-C 3 N 4 lamella (VO-WCN) in the interest of developing superior active ternary VO-WCN@CCS nanophotocatalyst for detoxification of levofloxacin (LF). The exceptional physicochemical properties of as-constructed samples were scrutinized via diverse characterization methods. After the optimization of CCS loading (30 wt%) and operational parameters, the VO-WCN@CCS(30) demonstrated ultramost photocatalytic efficiency toward LF decomposition (98 %) within 120 min reaction, which was 7.2, 9.9, and 19.1-fold greater than the pristine VO, WCN, and CCS, respectively. In the matter of catalyst reusability, the VO-WCN@CCS(30) could retain 88 % of initial performance after six consecutive disintegration cycles with negligible leached metals, and no evidence of variation was observed in the authenticated crystal structure. After thoroughly mineralization of the LF under ternary VO-WCN@CCS(30) nanocomposite for a duration of 300 min, ICP analysis exhibited the inconsequential amount of leached metals in the interest of catalyst stability. Encompassing the yolk-shell-structured CCS spheres into the superb stabilized heterogeneous VO-WCN prevails against self-oxidation and harsh surrounding conditions. The combination of the light-harvesting and modulated electronic traits of the yolk-shell configuration of CCS with the S-scheme VO-WCN system, this study shed light on a new generation of efficacious sulfide-based nanocomposites for the photo-decontamination of non-biodegradable pollutants. [ABSTRACT FROM AUTHOR]