Periodic Reporting for period 1 - USHPP (Unassisted photochemical water oxidation to solar hydrogen peroxide production)
Reporting period: 2021-01-01 to 2022-12-31
Currently, hydrogen peroxide (H2O2) is one of the most valued energy carriers, generating more energy than any other fuel without producing any pollutants. In recent years, the use of high-efficiency hydrogen peroxide fuel cells has also gained much attention to resolve the problems associated with the limitations of proton exchange membrane fuel cells; in addition, they have potential applications in space power systems.1–3 The energy density of 60 wt.% aqueous H2O2 (3.0 MJ L-1) is equivalent to that of compressed (35 MPa) H2 (2.8 MJ L-1) and much higher than gaseous H2.4 The MSCA-IF project “Unassisted photochemical water oxidation to solar hydrogen peroxide production (USHPP)” reports a system where natural resources (sun, air, and water) and waste (laboratory organic chemical waster or biowaste) were used for the production of future energy carrier H2O2. Using a photochemical approach, synthesising an efficient photocatalyst (PC) and adopting an efficient reaction system we have tried to make this possible. The research idea of this work was to generate H2O2 mainly focused on water oxidation/O2 reduction. Furthermore, the reduction of H+ ions to H2 in the conduction band along with water oxidation to H2O2 has shown the potential to resolve the major problem of gas separation associated with photochemical water splitting to H2 and O2 in a particulate system. Moreover, the USHPP project also projected the best use of in-situ generated reactive oxygen species (ROSs) in combination with biocatalysts/heterogeneous catalysts for the epoxidation of alkene, chemical conversion of organic/biomolecules to valuable chemicals, and photoinduced cancer treatment. Not much has been reported on a such hybrid approach combining photocatalysis, heterogeneous catalysis and biomedical applications. Work on the USHPP certainly increases the understanding of the challenges associated with the oxidation of water to H2O2, the potential for hybridization of photocatalysts with hetero/biocatalysts, the best possible use of photocatalysts in various sectors, and the contribution to a circular economy.
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.
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.
Papers published
1. Cd/Pt Precursor Solution for Solar H2 Production and in-situ Photochemical Synthesis of Pt Single-atom Decorated CdS Nanoparticles,
Pankaj Sharma,* Monika Sharma, Malcolm Dearg, Martin Wilding, Thomas J. A. Slater, and C. Richard A. Catlow,* Angewandte Chemie International Edition, 2023, https://doi.org/10.1002/anie.202301239.
https://orca.cardiff.ac.uk/id/eprint/158360
This publication has Golden Open Access.
https://epubs.stfc.ac.uk/work/53870743
https://publications.diamond.ac.uk/pubman/viewpublication?publicationId=15771
2. Enhanced H2O2 Production via Photocatalytic O2 Reduction over Structurally-Modified Poly(heptazine imide)
Pankaj Sharma,* Thomas J. A. Slater, Monika Sharma, Michael Bowker, * and C. Richard A. Catlow, * Chemistry of Materials, 34, 2022, 5511–5521.
https://doi.org/10.1021/acs.chemmater.2c00528
https://orca.cardiff.ac.uk/id/eprint/150524
Published as part of the Virtual Special Issue “John Goodenough at 100”.
This publication has Golden Open Access.
https://publications.diamond.ac.uk/pubman/viewpublication?publicationId=14944
3. Alkali metal-mediated reversible chemical hydrogen storage from seawater,
Pankaj Sharma,‡ J. Han,‡ J.H. Park,‡ D.Y. Kim,‡ J. Lee, D. Oh, N. Kim, D.-H. Seo, Y.-S Kim, S. J. Kang, S. M. Hwang, J.-W. Jang, JACS-Au, 1 (12), 2021, 2339-2348.
https://doi.org/10.1021/jacsau.1c00444
https://doi.org/10.1021/jacsau.1c00444
https://www.youtube.com/watch?v=n7xy1EPpZOE
This publication also has a Golden Open Access.
Under review collaborative work
1. Methane conversion to methanol using Au/ZSM-5 is promoted by carbon.
Jingxian Cao, Richard J. Lewis, Guodong Qi, Donald Bethell, Mark J. Howard, Brian Harrison, Bingqing Yao, Qian He, David J. Morgan, Fenglou Ni, Pankaj Sharma, Christopher J. Kiely, Xu Li, Feng Deng, Jun Xu, and Graham J. Hutchings, ACS Catalysis, cs-2023-01226j, Under Review
1. Cd/Pt Precursor Solution for Solar H2 Production and in-situ Photochemical Synthesis of Pt Single-atom Decorated CdS Nanoparticles,
Pankaj Sharma,* Monika Sharma, Malcolm Dearg, Martin Wilding, Thomas J. A. Slater, and C. Richard A. Catlow,* Angewandte Chemie International Edition, 2023, https://doi.org/10.1002/anie.202301239.
https://orca.cardiff.ac.uk/id/eprint/158360
This publication has Golden Open Access.
https://epubs.stfc.ac.uk/work/53870743
https://publications.diamond.ac.uk/pubman/viewpublication?publicationId=15771
2. Enhanced H2O2 Production via Photocatalytic O2 Reduction over Structurally-Modified Poly(heptazine imide)
Pankaj Sharma,* Thomas J. A. Slater, Monika Sharma, Michael Bowker, * and C. Richard A. Catlow, * Chemistry of Materials, 34, 2022, 5511–5521.
https://doi.org/10.1021/acs.chemmater.2c00528
https://orca.cardiff.ac.uk/id/eprint/150524
Published as part of the Virtual Special Issue “John Goodenough at 100”.
This publication has Golden Open Access.
https://publications.diamond.ac.uk/pubman/viewpublication?publicationId=14944
3. Alkali metal-mediated reversible chemical hydrogen storage from seawater,
Pankaj Sharma,‡ J. Han,‡ J.H. Park,‡ D.Y. Kim,‡ J. Lee, D. Oh, N. Kim, D.-H. Seo, Y.-S Kim, S. J. Kang, S. M. Hwang, J.-W. Jang, JACS-Au, 1 (12), 2021, 2339-2348.
https://doi.org/10.1021/jacsau.1c00444
https://doi.org/10.1021/jacsau.1c00444
https://www.youtube.com/watch?v=n7xy1EPpZOE
This publication also has a Golden Open Access.
Under review collaborative work
1. Methane conversion to methanol using Au/ZSM-5 is promoted by carbon.
Jingxian Cao, Richard J. Lewis, Guodong Qi, Donald Bethell, Mark J. Howard, Brian Harrison, Bingqing Yao, Qian He, David J. Morgan, Fenglou Ni, Pankaj Sharma, Christopher J. Kiely, Xu Li, Feng Deng, Jun Xu, and Graham J. Hutchings, ACS Catalysis, cs-2023-01226j, Under Review