Immobilising and Interfacing Poly(Heptazine Imide) Ionic Carbon Nitride for Photo(electro)catalytic Fuel and Chemical Production
type: CreativeWork
description: The production of fuels and other value-added chemicals from sunlight is one of the proposed sustainable pathways to fulfil the constantly increasing energy demand while pushing towards a carbon-neutral circular economy. Photocatalytic (PC) and photo(electro)catalytic (PEC) systems, based on a semiconductor/liquid electrolyte junction, are capable of converting and storing the energy from the sun into chemical bonds. Over the years, poly(heptazine imide) ionic carbon nitride, a cheap, non-toxic, noble metal-free polymeric semiconductor has been exploited mainly as photocatalyst, and more recently, as photoelectrocatalyst. Although the performance of this material in PEC systems has been improving, its application is still hindered by low photocurrent response and poor long-term stability due to its notably high recombination rates, inefficient charge separation and transport, and consequent photo-degradation. Moreover, its compatibility with bio-based systems for green fuel and chemical production has been poorly exploited and rationalised. This thesis tackles these challenges by introducing a versatile and facile method to synthesise highly performant carbon nitride photoanodes, which can be interfaced with metal- and enzyme-based catalysts for CO2-reduction and hydrogen production with record photocurrents and stabilities. State-of-the-art cyanamide-functionalised poly(heptazine imide) (PHI) ionic carbon nitride (NCNCNx) electrodes were produced by co-deposition with indium tin oxide (ITO) nanoparticles, binding agents and conductive bridges, on a thin alumina-coated FTO glass substrate. The Al2O3|ITO:NCNCNx photoelectrodes displayed remarkably low onset potential and an outstanding 1.4 ± 0.2 mA cm–2 at 1.23 V vs the reversible hydrogen electrode (RHE) when selectively oxidising 4-methylbenzyl alcohol. Detailed spectroscopic studies shine a light on electron extraction kinetics within the photoanode and show that the addition of the ITO nanoparticles significantly…
abstract: The production of fuels and other value-added chemicals from sunlight is one of the proposed sustainable pathways to fulfil the constantly increasing energy demand while pushing towards a carbon-neutral circular economy. Photocatalytic (PC) and photo(electro)catalytic (PEC) systems, based on a semiconductor/liquid electrolyte junction, are capable of converting and storing the energy from the sun into chemical bonds. Over the years, poly(heptazine imide) ionic carbon nitride, a cheap, non-toxic, noble metal-free polymeric semiconductor has been exploited mainly as photocatalyst, and more recently, as photoelectrocatalyst. Although the performance of this material in PEC systems has been improving, its application is still hindered by low photocurrent response and poor long-term stability due to its notably high recombination rates, inefficient charge separation and transport, and consequent photo-degradation. Moreover, its compatibility with bio-based systems for green fuel and chemical production has been poorly exploited and rationalised. This thesis tackles these challenges by introducing a versatile and facile method to synthesise highly performant carbon nitride photoanodes, which can be interfaced with metal- and enzyme-based catalysts for CO2-reduction and hydrogen production with record photocurrents and stabilities. State-of-the-art cyanamide-functionalised poly(heptazine imide) (PHI) ionic carbon nitride (NCNCNx) electrodes were produced by co-deposition with indium tin oxide (ITO) nanoparticles, binding agents and conductive bridges, on a thin alumina-coated FTO glass substrate. The Al2O3|ITO:NCNCNx photoelectrodes displayed remarkably low onset potential and an outstanding 1.4 ± 0.2 mA cm–2 at 1.23 V vs the reversible hydrogen electrode (RHE) when selectively oxidising 4-methylbenzyl alcohol. Detailed spectroscopic studies shine a light on electron extraction kinetics within the photoanode and show that the addition of the ITO nanoparticles significantly…
author: Pulignani, Carolina
language: eng
keywords: solar-to-chemical, biohybrid systems, photoelectrochemistry, solar fuels, sustainability, Carbon nitride, Renewable energy
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/0ec90c56-2e11-4101-9633-6a4a564e82f8/download
license: http://purl.org/NET/rdflicense/allrightsreserved
date published: 2024-10-25
date modified: 2026-07-22T22:24:30Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.117387