Systematic review on applicability of magnetic iron-oxides integrated photocatalysts for degradation of organic pollutants in water

Owing to biocompatibility, abundance, and low cost, magnetic iron oxides are well suited for the design of efficient and magnetically separable photocatalysts for water treatment. This review presents a detailed survey of magnetic iron oxide–integrated photocatalysts (MIOIPs), in which we have discussed essential conditions needed for designing of efficient MIOIPs for water purification. The synthesis methods and detailed experimental setups for fabrication of MIOIPs were discussed, and the integration manners of iron oxides (Fe2O3, Fe3O4, FeO, and ferrites) with binary, ternary, and quaternary non-magnetic photocatalysts have been categorized. The mechanistic view of enhanced photocatalytic activity caused by different MIOIPs under various light sources was also elaborately argued. The role of various reactive species in photocatalytic oxidative degrading of organic pollutants was investigated. Altogether, this review article has compressively considered and discussed various signs of advancements made toward the synthesis of MIOIPs and their stability, recyclability, and catalytic efficacy for wastewater treatment

Photocatalytic inactivation of viruses using graphitic carbon nitride-based photocatalysts:Virucidal performance and mechanism

The prevalence of lethal viral infections necessitates the innovation of novel disinfection techniques for contaminated surfaces, air, and wastewater as significant transmission media of disease. The instigated research has led to the development of photocatalysis as an effective renewable solar-driven technology relying on the reactive oxidative species, mainly hydroxyl (OH●) and superoxide (O2●−) radicals, for rupturing the capsid shell of the virus and loss of pathogenicity. Metal-free graphitic carbon nitride (g-C3N4), which possesses a visible light active bandgap structure, low toxicity, and high thermal stability, has recently attracted attention for viral inactivation. In addition, g-C3N4-based photocatalysts have also experienced a renaissance in many domains, including environment, energy conversion, and biomedical applications. Herein, we discuss the three aspects of the antiviral mechanism, intending to highlight the advantages of photocatalysis over traditional viral disinfection techniques. The sole agenda of the review is to summarize the significant research on g-C3N4-based photocatalysts for viral inactivation by reactive oxidative species generation. An evaluation of the photocatalysis operational parameters affecting viral inactivation kinetics is presented. An overview of the prevailing challenges and sustainable solutions is presented to fill in the existing knowledge gaps. Given the merits of graphitic carbon nitride and the heterogeneous photocatalytic viral inactivation mechanism, we hope that further research will contribute to preventing the ongoing Coronavirus pandemic and future calamities

Recent advances in noble metal free doped graphitic carbon nitride based nanohybrids for photocatalysis of organic contaminants in water: A review

Extensive contamination of water bodies by textile dyeing industries, organic pollutants and agricultural waste has emerged water pollution as one of the major global environmental crisis. The effect of this gross negligence is posing serious threats to human health therefore today; conserving water resources for the essence of life is of grave concern. Recently, advancements in photocatalytic properties of graphitic carbon nitride (g-C3N4) for wastewater treatment have gained tremendous interest in research. However, pristine g-C3N4 suffers from bottlenecks such as low surface area, rapid recombination of photo-generated electron–hole pairs and insufficient light absorption which thereby, reduces the photocatalytic degradation activity. Hitherto, noble metals have been widely utilized as dopants but are cost ineffective, rarely found and are difficult to recover. In this updated and all-inclusive review we have briefly discussed photocatalysis mechanism, primarily focused on non-precious elemental doping via various synthesis techniques of noble metal free doped g-C3N4 photocatalysts. Typically metal, non-metal, rare earth metal doping and co-doping have been explored, which demonstrates the synergistic behavior of the doped nanocomposites in modulation of electronic structure, broaden the visible light absorption range, enhancement in photocatalytic wastewater remediation ability to obtain maximum pollutant eradication. Summary remarks conclude the review with valuable knowledge of noble metal free doped g-C3N4 photocatalysts for water purification and sheds light on current challenges and crucial issues associated with its commercialization. The future aspect aims at designing of efficient solar light driven photocatalysts for application in various domains i.e. production of H2 and O2, reduction of CO2, practical use of solar cells, treatment of wastewater, air purification and environmental conservatio

Persulfate-aided modified graphitic carbon nitride-based photocatalysts for wastewater treatment:synergistic mechanism

The metal-free graphitic carbon nitride (GCN) has ignited research in the realm of sulfate radical-based AOPs for aqueous pollutant degradation owing to the tunable optoelectronic properties. Upon light irradiations, the electronic excitations in GCN cause peroxo (O-O) bond cleavage in peroxydimonosulfate (PDS) and peroxymonosulfate (PMS) oxidants to release SO4 − and ·OH reactive oxidative species. The SO4 − radicals benefited from higher oxidation potential (2.5–3.1V), longer half-life period (4×10−5s), and responsiveness in the pH range. The synergistic mechanism of GCN-mediated PS/PMS photoactivation confirms the generation of ·OH to overcome the poor reductive potential of GCN and fastens the degradation rate of the reaction. With the advancement in surface modification strategies, researchers have explored the methods of introducing functional groups for increasing the surface-active sites to activate PMS/PDS over GCN.</p