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

• DOI: 10.1021/acsami.3c09363
• Publication Date: 2023-09-28T19:37:44Z
• Authors: Mattia Benedet; Andrea Gallo; Chiara Maccato; Gian Andrea Rizzi; Davide Barreca; Oleg I. Lebedev; Evgeny Modin; Ruairi McGlynn; Davide Mariotti; Alberto Gasparotto
• Keywords: [CHIM.MATE] Chemical Sciences/Material chemistry; nanoarchitectures; 500; [CHIM.CATA] Chemical Sciences/Catalysis; [CHIM.MATE]Chemical Sciences/Material chemistry; [CHIM.CATA]Chemical Sciences/Catalysis; Electrical apparatus and materials; 540; 530; graphitic carbon nitride; electrophoretic deposition; [CHIM.OTHE] Chemical Sciences/Other; oxygen evolution reaction; [CHIM] Chemical Sciences; [CHIM]Chemical Sciences; plasma-enhanced chemical vapor deposition; MnO2; [CHIM.OTHE]Chemical Sciences/Other

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.