Mir Sayed Shah Danish, Liezel L. Estrella, Ivy Michelle A. Alemaida, Anton Lisin, Nikita Moiseev, Mikaeel Ahmadi, Massoma Nazari, Mohebullah Wali, Hameedullah Zaheb, Tomonobu Senjyu
Along with industrialization and rapid urbanization, environmental remediation is globally a perpetual concept to deliver a sustainable environment. Various organic and inorganic wastes from industries and domestic homes are released into water systems. These wastes carry contaminants with detrimental effects on the environment. Consequently, there is an urgent need for an appropriate wastewater treatment technology for the effective decontamination of our water systems. One promising approach is employing nanoparticles of metal oxides as photocatalysts for the degradation of these water pollutants. Transition metal oxides and their composites exhibit excellent photocatalytic activities and along show favorable characteristics like non-toxicity and stability that also make them useful in a wide range of applications. This study discusses some characteristics of metal oxides and briefly outlined their various applications. It focuses on the metal oxides TiO2, ZnO, WO3, CuO, and Cu2O, which are the most common and recognized to be cost-effective, stable, efficient, and most of all, environmentally friendly for a sustainable approach for environmental remediation. Meanwhile, this study highlights the photocatalytic activities of these metal oxides, recent developments, challenges, and modifications made on these metal oxides to overcome their limitations and maximize their performance in the photodegradation of pollutants. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Strategic Research Project Center, University of the Ryukyus, 1 Senbaru, 9030213, Japan; Department of Energy Engineering, Kabul University, Jamal Mina 1006, Afghanistan; Department of Chemistry, Silliman University, Hibbard Avenue, Dumaguete City, 6200, Negros Oriental, Philippines; Department of Chemistry, University of San Carlos—Talamban Campus, Talamban, Cebu City, 6000, Philippines; Financial Faculty, Financial University under the Government of the Russia Federation, Moscow, 125993, Russian Federation; Department of Mathematical Methods in Economics, Plekhanov Russia University of Economics, Moscow, 117997, Russian Federation; Department of Electrical and Electronics Engineering, University of the Ryukyus, 1 Senbaru, 9030213, Japan; Infrastructure Project Management Team (IPMT), Pacific Architects and Engineers (PAE)-CSSP, Zohak Village, Kabul, 1002, Afghanistan; Department of Electrical and Electronics Engineering, Kabul University, Jamal Mina 1006, Afghanistan
