0D/3D MoS2-NiS2/N-doped graphene foam composite for efficient overall water splitting

• Published in: Applied catalysis. B, Environmental Environmental, 2019-10, Vol.254, p.15-25
• Main Authors: Kuang, Panyong, He, Min, Zou, Haiyuan, Yu, Jiaguo, Fan, Ke
• Format: Article
• Language: English
• Subjects: Bimetallic sulfides; Bimetals; Catalysis; Catalysts; Charge transfer; Chemical synthesis; Electrochemistry; Graphene; Hydrogen evolution reactions; Interfaces; Mass transport; Molybdenum disulfide; Nanoparticles; Nerve growth factor; Nitrogen; Nitrogen-doped graphene foam; Overall water splitting; Oxygen evolution reactions; Splitting; Strong chemical interactions; Sulfides; Synergistic effect; Three-dimensional; Water splitting
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2019.04.072

[Display omitted] •Low cost melamine sponge was used to prepare N-doped graphene foam (NGF).•MoS2-NiS2/NGF composite was prepared by hydrothermal and CVD methods.•NGF facilitates the transport of electrons, ions, and gases.•Heterointerfaces in MoS2-NiS2 boost the dissociation of H2O molecules.•MoS2-NiS2/NGF composite with enhanced electrocatalytic activity. Electrochemical water splitting is strongly dependent on mass transport and active sites, however, the difficulty in facilitating mass transport and exposing sufficient active sites is the major bottleneck for both half reactions of the overall water splitting, i.e., hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). To address these two issues, a facile and economical strategy is demonstrated for the preparation of the bimetallic sulfides anchored three-dimensional (3D) nitrogen-doped graphene foam (MoS2-NiS2/NGF) hybrid for efficient overall water splitting. As a result, strong interactions occur between MoS2-NiS2 nanoparticles and NGF with unique 3D interconnected tubular hollow structure, leading to the superior performance towards HER and OER. The overpotential and charge transfer resistance of the hybrid are much lower than those of the bare NGF, MoS2/NGF, NiS2/NGF, and physically mixed MoS2-NiS2 + NGF, which can be attributed to the synergistic effect of NGF and bimetallic sulfides with hetero interfaces, thus endowing MoS2-NiS2/NGF abundant active sites and diversified pathways for highly-efficient transport of mass and electron. This bifunctional catalyst also exhibits excellent overall water splitting capability with a current density of 10 mA cm−2 at 1.64 V, which provides a platform for the synthesis of large-scale and cost-efficient catalysts for water splitting.