Progress on the photocatalytic reduction of hexavalent Cr (VI) using engineered graphitic carbon nitride

• Published in: Process safety and environmental protection Vol. 152; pp. 663 - 678
• Main Authors: Hasija, Vasudha, Raizada, Pankaj, Singh, Pardeep, Verma, Narinder, Khan, Aftab Aslam Parwaz, Singh, Arachana, Selvasembian, Rangabhashiyam, Kim, Soo Young, Hussain, Chaudhery Mustansar, Nguyen, Van-Huy, Le, Quyet Van
• Format: Journal Article
• Language: English
• Published: Rugby Elsevier B.V 01.08.2021; Elsevier Science Ltd
• Subjects: Additives; Aquatic environment; Carbon; Carbon nitride; Catalysts; Chromium; Conduction bands; Cr (VI) reduction; Efficiency; Energy utilization; Enhancement strategies; Graphitic carbon nitride; Heterojunctions; Interface stability; Light sources; Optical properties; Organic acids; Oxidation; Photocatalysis; Photocatalytic activity; Photoreduction; Reaction parameters; Solar energy; Valence; Photocatalytic activity; Cr (VI) reduction; Enhancement strategies; Graphitic carbon nitride; Reaction parameters
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2021.06.042

[Display omitted] The existence of chromium in hexavalent oxidation state is highly toxic to aquatic environment. Photocatalytic reduction of hexavalent Cr (VI) into Cr (III) has emerged as a desirable technology due to their prospect in solar energy utilization, high efficiency and low cost. Graphitic carbon nitride (g-C3N4)-based photocatalysts are ideal for Cr (VI) reduction due to their inherent features including; visible-light responsive narrow bandgap, suitable conduction band potential, high physicochemical stability, unique optical and electronic properties. Herein, various surface-interface strategies to modify g-C3N4 including heterojunction formation, doping, structural regulation, co-catalyst loading and construction of nitrogen vacancies are elaborated for improving the Cr(VI) photoreduction efficiency. The review also highlights the effect of operational reaction conditions such solution pH, g-C3N4 dosage, Cr (VI) concentration, temperature, light source, organic acid additives and co-existing ions influencing Cr (VI) reduction efficiency. Finally, we attempt to propose the existing issues based on the current research and future aspects of engineered g-C3N4 for Cr (VI) photoreduction.