Nanoengineered Advanced Materials for Enabling Hydrogen Economy: Functionalized Graphene-Incorporated Cupric Oxide Catalyst for Efficient Solar Hydrogen Production

Goutam Kumar Dalapati; Saeid Masudy-Panah; Roozbeh Siavash Moakhar; Sabyasachi Chakrabortty; Siddhartha Ghosh; Ajay Kushwaha; Reza Katal; Chin Sheng Chua; Gong Xiao; Sudhiranjan Tripathy; Seeram Ramakrishna

doi:10.1002/gch2.201900087

Nanoengineered Advanced Materials for Enabling Hydrogen Economy: Functionalized Graphene-Incorporated Cupric Oxide Catalyst for Efficient Solar Hydrogen Production

Glob Chall. 2020 Jan 24;4(3):1900087. doi: 10.1002/gch2.201900087. eCollection 2020 Mar.

Authors

Goutam Kumar Dalapati^{1

2

3

4}, Saeid Masudy-Panah^{5

6}, Roozbeh Siavash Moakhar⁷, Sabyasachi Chakrabortty⁸, Siddhartha Ghosh¹, Ajay Kushwaha⁹, Reza Katal¹⁰, Chin Sheng Chua², Gong Xiao^{5

6}, Sudhiranjan Tripathy², Seeram Ramakrishna⁴

Affiliations

¹ Department of Physics SRM University - AP Amaravati Andhra Pradesh 522502 India.
² Institute of Materials Research and Engineering ASTAR (Agency for Science, Technology and Research) 2 Fusionopolis Way; Innovis, #08-03 Singapore 138634 Singapore.
³ School of Engineering & Innovation The Open University Milton Keynes MK7 6AA UK.
⁴ Center for Nanofibers and Nanotechnology Faculty of Engineering National University of Singapore Singapore 117576 Singapore.
⁵ Energy Electronic Systems (LEES) Singapore-MIT Alliance for Research and Technology (SMART) Centre 1 CREATE Way, #09-01/02 CREATE Tower Singapore 138602 Singapore.
⁶ Electrical and Computer Engineering National University of Singapore Singapore 119260 Singapore.
⁷ Department of Materials Science and Engineering Sharif University of Technology Tehran 11155-9466 Iran.
⁸ Department of Chemistry SRM University - AP Amaravati Andhra Pradesh 522502 India.
⁹ Discipline of Metallurgy Engineering and Materials Science Indian Institute of Technology Indore Simrol Indore Madhya Pradesh 453552 India.
¹⁰ Department of Civil & Environmental Engineering National University of Singapore Singapore 119260 Singapore.

Abstract

Cupric oxide (CuO) is a promising candidate as a photocathode for visible-light-driven photo-electrochemical (PEC) water splitting. However, the stability of the CuO photocathode against photo-corrosion is crucial for developing CuO-based PEC cells. This study demonstrates a stable and efficient photocathode through the introduction of graphene into CuO film (CuO:G). The CuO:G composite electrodes are prepared using graphene-incorporated CuO sol-gel solution via spin-coating techniques. The graphene is modified with two different types of functional groups, such as amine (-NH₂) and carboxylic acid (-COOH). The -COOH-functionalized graphene incorporation into CuO photocathode exhibits better stability and also improves the photocurrent generation compare to control CuO electrode. In addition, -COOH-functionalized graphene reduces the conversion of CuO phase into cuprous oxide (Cu₂O) during photo-electrochemical reaction due to effective charge transfer and leads to a more stable photocathode. The reduction of CuO to Cu₂O phase is significantly lesser in CuO:G-COOH as compared to CuO and CuO:G-NH₂ photocathodes. The photocatalytic degradation of methylene blue (MB) by CuO, CuO:G-NH₂ and CuO:G-COOH is also investigated. By integrating CuO:G-COOH photocathode with a sol-gel-deposited TiO₂ protecting layer and Au-Pd nanostructure, stable and efficient photocathode are developed for solar hydrogen generation.

Keywords: Raman spectroscopy; photocatalytic degradation; photocorrosion stability; solar hydrogen.