Title

Cu-Ion-Implanted and Polymeric Carbon Nitride-Decorated TiO2Nanotube Array for Unassisted Photoelectrochemical Water Splitting

Publication Name

ACS Applied Materials and Interfaces

Abstract

Photoelectrochemical (PEC) water splitting over TiO2 photoanodes is a promising strategy for hydrogen production due to its eco-friendly, energy-saving, and low-cost nature. However, the intrinsic drawbacks of TiO2, i.e., the too wide band gap and rapid exciton recombination, significantly limit further enhancement of its performance. Herein, we report a TiO2 nanotube array (TNA), which is implanted by Cu ions and decorated by polymeric carbon nitride (PCN) nanosheets, as a photoanode for the high-efficiency PEC water splitting. In such designed material, Cu-ion implantation can effectively tailor the electronic structure of TiO2, thus narrowing the band gap and enhancing the electronic conductivity. Meanwhile, the PCN decoration induces TiO2/PCN heterojunctions, enhancing the visible light absorption and accelerating the exciton separation. Upon this synergistic effect, the modified TNA photoanode shows significantly improved PEC capability. Its photocurrent density, solar-to-hydrogen efficiency, and applied bias photon-to-current efficiency achieve 1.89 mA cm-2 at 1.23 VRHE (V vs reversible hydrogen electrode), 2.31%, and 1.20% at 0.46 VRHE, respectively. Importantly, this modified TNA supported on a meshlike Ti substrate can be readily integrated with a perovskite solar cell to realize unassisted PEC water splitting.

Open Access Status

This publication is not available as open access

Volume

13

Issue

37

First Page

44184

Last Page

44194

Funding Number

TD13-5077

Funding Sponsor

Australian Research Council

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Link to publisher version (DOI)

http://dx.doi.org/10.1021/acsami.1c09665