Poly Meta-Aminophenol (PmAP) as a Solid-State Electron Mediator in the Z-Scheme, Ag3PO4/CoFe2O4 Heterojunction: Mineralization of Highly Concentrated Bisphenol-A and Reactive Dyes Water Pollutants.

This study demonstrated the effectiveness of poly meta-aminophenol (PmAP) as a solid electron mediator in the Z-scheme photocatalytic system for organic pollutants (viz. bisphenol-A and reactive dyes) mineralization and also illustrated how PmAP transported the photogenerated electrons from an O2-emitting photocatalyst (Ag3PO4) to a H2-emitting photocatalyst (CoFe2O4) enabling enhanced photocatalytic activity under visible light irradiation. The PmAP/Ag3PO4-CoFe2O4 (PAC-10), was prepared by a two-step process and characterized by various analytical methods to assess the impact of PmAP on optical, photocatalytic, and electrochemical characteristics of the CoFe2O4 (CFO)/Ag3PO4 composite. The morphological investigation revealed that the PmAP sheet was nicely decorated with evenly distributed Ag3PO4 and CoFe2O4 particles. The M-S plot and impedance analyses were used to assess the electrochemical capabilities of the catalyst. Z-scheme charge transfer pathways were well supported by the radical trapping experiment and HRTEM analysis of Pt photodeposited PAC-10 photocatalysts during the photoreaction. Because of its magnetic nature and ease of synthesis, the PAC-10 offers an easily recyclable Z-scheme photocatalytic system that has the potential for purifying wastewater with high concentrations (up to 100 mg/L) of organic pollutants within 30 min of visible light exposition.

Synergistic cobalt oxide/reduced graphene oxide/biochar nano-composite catalyst: harnessing the power of the catalyst for sustainable remediation of organic dyes and chromium(vi).

The exponential growth of industrial activities has led to a significant rise in the release of organic effluents, containing hazardous heavy metals and dyes, into the environment. These pollutants exhibit resistance to conventional biodegradation processes and are associated with carcinogenic properties, posing a severe threat to living organisms. In this context, the present research endeavours to address this environmental challenge through the development of an affordable and efficient photocatalyst, the Co3O4/reduced graphene oxide/biochar (CBG-10) heterostructure. The structural analysis of CBG-10, conducted through various techniques such as XRD, XPS, SEM, and optical property measurements, demonstrates its potential as a highly effective and easily recoverable catalyst for the mineralization of persistent pollutants like methylene blue, malachite green, and hexavalent Cr(vi). The recyclability of CBG-10 was confirmed through XRD studies, highlighting its stability and practical usability in wastewater purification. The photocatalytic behaviour of the catalyst was attributed to the generation of hydroxyl (˙OH) and superoxide radicals (˙O2-) during visible light illumination, as revealed by quenching experiments. The cost-effectiveness and stability of CBG-10 position it as a promising solution for addressing the challenges associated with the removal of stubborn organic contaminants from wastewater, thereby contributing to environmental protection and public health.