1. Enhanced H2O2 production via photocatalytic O2 reduction over structurally-modified poly(heptazine imide): Solar H2O2 produced by O2 reduction or water oxidation provides a green, efficient and ecological alternative to the industrial anthraquinone process and H2/O2 direct-synthesis. Thus, there is a pressing need for the development of an effective photocatalyst that could greatly increase photocatalytic H2O2 production. Stimulated by the earlier reported strategies, we have synthesized a new photocatalyst that combines properties including a higher intrinsic surface area, modified electronic structure, reduced band gap, and defect sites for enhanced H2O2 production. To this end, we have successfully synthesised an alkali metal-halide (MX, M = K+; Li+, X = Cl-) modulated C-N based poly(heptazine imide) (PHI) molecular photocatalyst, MX→PHI for selective photochemical oxygen reduction reaction (PCORR) to produce a much higher yield of H2O2 than obtained previously. The present structurally modulated MX→PHI photocatalyst was synthesized by facile polymerization of an environmentally benign precursor, urea, in the presence of alkali metal halides. We report efficient photocatalytic H2O2 production at a rate of 73.4 mM h-1 in the presence of alcohols (laboratory waste chemicals used for rinsing the glassware) on a structurally-engineered catalyst, alkali metal-halide modulated poly(heptazine imide) (MX→PHI).
2. Cd/Pt precursor solution for solar H2 production and in-situ synthesis of Pt single-atom decorated CdS for their greater application in photocatalytic H2O2 production:
Despite extensive efforts to develop high-performance H2 evolution catalysts, this remains a major challenge. Here, we demonstrate the use of Cd/Pt precursor solutions for significant photocatalytic H2 production (154.7 mmol g-1 h-1), removing the need for a pre-synthesized photocatalyst. Importantly, the direct use of a precursor suspension, without using any complex photocatalyst synthesis process and organic solvents, outperforms most of the earlier reported photocatalysts for H2 production for particulate systems. In addition, we also report the simultaneous in-situ synthesis of Pt single-atoms anchored CdS nanoparticles (PtSA-CdSIS) during photoirradiation.
3. Photochemical oxidative H2O2 production as a sustainable approach for the coeval production of two energy carriers: H2O2 and H2 (an UNPUBLISHED WORK)
Currently, hydrogen peroxide (H2O2) and molecular hydrogen (H2) are the two most valued energy carriers, generating more energy than any other fuel without producing any pollutants. Here, we report photochemical oxidative H2O2 generation using monoclinic bismuth vanadate (m-BiVO4) and solar-assisted direct two-electron H2O splitting to generate both H2O2 and H2m-BiVO4 in conjugation with graphitic carbon nitride (g-C3N4) in the presence of phosphate ions under acidic conditions. The simultaneous generation of two different phase products (H2O2 in the liquid phase and H2 in the gas phase) has great significance in terms of ease of separation compared with the conventional photochemical particulate system, where the separation of two gaseous products remains a significant challenge. Like the earlier two publications, this research article also includes detailed photocatalysts characterisation, performance evaluation, mechanistic studies of photochemical reactions, etc.
