In-situ local phase-transitioned MoSe2 in La0.5Sr0.5CoO3-δ heterostructure and stable overall water electrolysis over 1000 hours

Abstract

Developing efficient bifunctional catalysts for overall water splitting that are earth-abundant, cost-effective, and durable is of considerable importance from the practical perspective to mitigate the issues associated with precious metal-based catalysts. Herein, we introduce a heterostructure comprising perovskite oxides (La 0.5 Sr 0.5 CoO 3– δ ) and molybdenum diselenide (MoSe 2 ) as an electrochemical catalyst for overall water electrolysis. Interestingly, formation of the heterostructure of La 0.5 Sr 0.5 CoO 3– δ and MoSe 2 induces a local phase transition in MoSe 2 , 2 H to 1 T phase, and more electrophilic La 0.5 Sr 0.5 CoO 3– δ with partial oxidation of the Co cation owing to electron transfer from Co to Mo. Together with these synergistic effects, the electrochemical activities are significantly improved for both hydrogen and oxygen evolution reactions. In the overall water splitting operation, the heterostructure showed excellent stability at the high current density of 100 mA cm −2 over 1,000 h, which is exceptionally better than the stability of the state-of-the-art platinum and iridium oxide couple.

Utilizing ion leaching effects for achieving high oxygen-evolving performance on hybrid nanocomposite with self-optimized behaviors

“…Therefore, how to simultaneously benefit from the advantages of ion leaching effects and stabilize perovskite crystalline matrix remains an open question. Compared with pure-phase catalysts, hybrid materials, with much larger physicochemical property degrees of freedom 4,[26][27][28] , can offer tremendous possibilities for us to design promising candidates to exert positive ion leaching effects and protect perovskite crystalline matrix.…”

Atomic Layer Deposition of MoSe2 Nanosheets on TiO2 Nanotube Arrays for Photocatalytic Dye Degradation and Electrocatalytic Hydrogen Evolution

“…The interlayer lattice spacing of 0.28 nm and 0.17 nm were unambiguously ascribed to the (100) and (110) planes, respectively, revealing in-plane hexagonal MoSe2 growth. 38 The hexagonal structure of the as-deposited MoSe2 was further confirmed by Raman spectroscopy. According to the group theory analysis, hexagonal 2H MoSe2 structure belongs to the D6h group characterized by four Raman-active modes, three in-plane E1g, E 1 2g, and E 2 2g, and one out-of-plane A1g.…”

Design of Hierarchical Porosity Via Manipulating Chemical and Microstructural Complexities in High‐Entropy Alloys for Efficient Water Electrolysis

“…Therefore, the OH/OOH‐rich active intermediates were formed on the dealloyed HEA surface, which contributes positively to the OER activity. [ 37 , 38 ] In addition, the energy efficiency at 100 mA cm −2 of water electrolysis using the (dealloyed HEA)||(dealloyed HEA) configuration was 83.4% according to the method in the literature, [ 39 , 40 ] which is much higher than that of the typical noble‐metal‐based water electrolysis (≈70%). Even considering the industrial operating stability as an important metric, the assembled cell can still keep an average voltage of 1.95 V at a large current density of 500 mA cm −2 over 240 h (Figure S30 , Supporting Information).…”