Atomic layer deposition-triggered hierarchical core/shell stable bifunctional electrocatalysts for overall water splitting

The precise design of nanomaterials is a promising approach, but remains a challenge toward the development of highly efficient catalysts in water splitting applications. Herein, a facile three-step process to rationally design advanced NiCo2O4/MoO2@atomic layer deposition (ALD)-NiO heteronanostructure arrays on a nickel foam substrate is reported. By effective interface construction, the optimal electronic structure and coordination environment are created at the interface in the heteronanostructure, which can provide rich reaction sites and short ion diffusion paths. Notably, density functional theory calculations reveal that the MoO2@ALD-NiO nanointerface exhibits highly appropriate energetics for alkaline oxygen/hydrogen evolution reactions (OER/HER), thereby accelerating the enhancement in electrochemical activities. Benefiting from the heteronanostructure containing abundant nanointerfaces, NiCo2O4/MoO2@ALD-NiO displays remarkable HER (57.1 mV at 10 mA cm−2) and OER (372.3 mV at 100 mA cm−2) activities and excellent long-term stability in a 1 M KOH solution. This study provides new insight into the catalytic design of cost-effective electrocatalysts for future renewable energy systems.11Nsciescopu

Role of quaternary ammonium compound immobilized metallic graphene oxide in PMMA/PEG membrane for antibacterial, antifouling and selective gas permeability properties

Recently, there is a high demand for development of polymeric membrane for their widespread technological applications. Polymer blends incorporation with inorganic composite particles is the most effective strategy for obtaining antifouling, antibacterial, gas and water permeable membrane materials. However, their biological and surface properties are always hindered by the inefficient interaction of filler into polymer matrix because it is distributed into the bulk membrane matrix. In this study, graphene oxide nanosheets are incorporated with metal (Ag)/metal oxide (ZnO) composite filler (MGO) followed by surface modification with quaternary cetyltrimethylammonium bromide (CTAB) to enhance non-covalent interactions between filler and poly methyl methacrylate (PMMA)/polyethylene glycol (PEG) blend membrane. The membrane was utilized for improving antifouling, antibacterial and gas permeability of membrane. Our results indicated that CTAB-modified filler (CTAB@MGO) was bonded to the polymer blend membrane without affecting the membranes’ physicochemical properties. The prepared CTAB@MGO–PMMA/PEG membrane showed excellent antibacterial property against model Escherichia coli bacteria. The antifouling activity and CTAB stability results of modified blend membrane ensured reduced bovine serum albumin adsorption and slow dissociation of surfactant molecules, respectively. The CTAB@MGO–PMMA/PEG blend membrane also showed promising gas permeability results with hydrogen (H2), nitrogen (N2) and carbon dioxide (CO2). The presented approach highlights the potential of surface modification of filler and introduces them in polymeric membrane as a simple, easy and cost-effective strategy for preparing antifouling and gas/water permeable polymeric membranes