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

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 (La0.5Sr0.5CoO3?????) and molybdenum diselenide (MoSe2) as an electrochemical catalyst for overall water electrolysis. Interestingly, formation of the heterostructure of La0.5Sr0.5CoO3????? and MoSe2 induces a local phase transition in MoSe2, 2???H to 1???T phase, and more electrophilic La0.5Sr0.5CoO3????? 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

Structure and properties of electrodeposited Ni-Co-YZA composite coatings

The aim is to develop an economical composite coating with high thermal stability. Ni-Co alloys are found to possess better thermal, physical and mechanical properties compared to Ni. Also, oxide particles as distributed phase can impart better thermal stability. Hence, particulates of composite Yttria stabilised zirconia, a commonly used high temperature material and alumina (YZA) were reinforced in various Ni-Co alloy matrices through electrodeposition. The influence of YZA on the microhardness, tribology and corrosion behaviour of Ni-Co alloys with Co contents of 0 wt.%, 17 wt.%, 38 wt.% and 85 wt.% was evaluated. Optical and Scanning Electron Microscopy (SEM) confirmed the presence of YZA particles and Energy Dispersive X-ray Analysis (EDX) revealed the composition. Tribology testing showed that composite containing 38 wt.% Co displayed better wear resistance. It was found from the immersion corrosion studies that Ni-17Co-YZA coating displayed improved corrosion resistance. Thermal stability studies showed that Ni-85Co-YZA coating retained its microhardness at temperatures of 600oC. Thus, these coatings can be tailored for various applications by varying the cobalt content