Controllable Anchoring of Graphitic Carbon Nitride on MnO2 Nanoarchitectures for Oxygen Evolution Electrocatalysis

Mattia Benedet; Andrea Gallo; Chiara Maccato; Gian Andrea Rizzi; Davide Barreca; Oleg I Lebedev; Evgeny Modin; Ruairi McGlynn; Davide Mariotti; Alberto Gasparotto

doi:10.1021/acsami.3c09363

Controllable Anchoring of Graphitic Carbon Nitride on MnO₂ Nanoarchitectures for Oxygen Evolution Electrocatalysis

ACS Appl Mater Interfaces. 2023 Oct 11;15(40):47368-47380. doi: 10.1021/acsami.3c09363. Epub 2023 Sep 28.

Authors

Mattia Benedet^{1

2}, Andrea Gallo¹, Chiara Maccato^{1

2}, Gian Andrea Rizzi^{1

2}, Davide Barreca², Oleg I Lebedev³, Evgeny Modin⁴, Ruairi McGlynn⁵, Davide Mariotti⁵, Alberto Gasparotto^{1

2}

Affiliations

¹ Department of Chemical Sciences, Padova University and INSTM, 35131 Padova, Italy.
² CNR-ICMATE and INSTM, Department of Chemical Sciences, Padova University, 35131 Padova, Italy.
³ Laboratoire CRISMAT, UMR 6508 CNRS/ENSICAEN/UCBN, 14050 Caen Cedex 4, France.
⁴ CIC nanoGUNE BRTA, Donostia, 20018 San Sebastian, Spain.
⁵ School of Engineering, Ulster University, 2-24 York Street, Belfast BT15 1AP, Northern Ireland.

Abstract

The design and fabrication of eco-friendly and cost-effective (photo)electrocatalysts for the oxygen evolution reaction (OER) is a key research goal for a proper management of water splitting to address the global energy crisis. In this work, we focus on the preparation of supported MnO₂/graphitic carbon nitride (g-CN) OER (photo)electrocatalysts by means of a novel preparation strategy. The proposed route consists of the plasma enhanced-chemical vapor deposition (PE-CVD) of MnO₂ nanoarchitectures on porous Ni scaffolds, the anchoring of controllable g-CN amounts by an amenable electrophoretic deposition (EPD) process, and the ultimate thermal treatment in air. The inherent method versatility and flexibility afforded defective MnO₂/g-CN nanoarchitectures, featuring a g-CN content and nano-organization tunable as a function of EPD duration and the used carbon nitride precursor. Such a modulation had a direct influence on OER functional performances, which, for the best composite system, corresponded to an overpotential of 430 mV at 10 mA/cm², a Tafel slope of ≈70 mV/dec, and a turnover frequency of 6.52 × 10^-3 s^-1, accompanied by a very good time stability. The present outcomes, comparing favorably with previous results on analogous systems, were rationalized on the basis of the formation of type-II MnO₂/g-CN heterojunctions, and yield valuable insights into this class of green (photo)electrocatalysts for end uses in solar-to-fuel conversion and water treatment.

Keywords: MnO2; electrophoretic deposition; graphitic carbon nitride; nanoarchitectures; oxygen evolution reaction; plasma-enhanced chemical vapor deposition.