title: Efficient electrochemical water oxidation in neutral and near-neutral systems with a nanoscale silver-oxide catalyst.
abstract: In electrocatalytic water splitting systems pursuing for renewable energy using sunlight, developing robust, stable and easily accessible materials operating under mild chemical conditions is pivotal. We present here a unique nanoparticulate type silver-oxide (AgOx-NP) based robust and highly stable electrocatalyst for efficient water oxidation. The AgOx-NP is generated in situ in a HCO3(-)/CO2 system under benign conditions. Micrographs show that they exhibit a nanoscale box type squared nano-bipyramidal configuration. The oxygen generation is initiated at low overpotential, and a sustained O2 evolution current density of >1.1 mA cm(-2) is achieved during prolonged-period water electrolysis. The AgOx-NP electrocatalyst performs exceptionally well in metal-ion free neutral or near-neutral carbonate, phosphate and borate buffers relative to recently reported Co-oxide and Ni-oxide based heterogeneous electrocatalysts, which are unstable in metal-ion free electrolytes and tend to deactivate with time and lose catalytic performance during long-term experimental tests.
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, P.O. Box 9502, 2300 RA Leiden, The Netherlands. khurram.joya@gmail.com and Department of Chemistry, University of Engineering and Technology, GT Road 54890 Lahore, Punjab, Pakistan. khurram_joya@uet.edu.pk and Division of Physical Sciences and Engineering, KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), 4700 KAUST, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Khurram S
authors.initials: KS
authors.lastname: Joya
authors.affiliation: Department of Chemistry, University of Engineering and Technology, GT Road 54890 Lahore, Punjab, Pakistan. khurram_joya@uet.edu.pk.
authors.forename: Zahoor
authors.initials: Z
authors.lastname: Ahmad
authors.affiliation: Faculty of Materials Science and Engineering, Ghulam Ishaq Khan (GIK) Institute of Engineering Sciences and Technology, Topi 23640, Khyber Pakhtunkhaw, Pakistan.
authors.forename: Yasir F
authors.initials: YF
authors.lastname: Joya
authors.affiliation: Division of Physical Sciences and Engineering, KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), 4700 KAUST, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Angel T
authors.initials: AT
authors.lastname: Garcia-Esparza
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, P.O. Box 9502, 2300 RA Leiden, The Netherlands. khurram.joya@gmail.com.
authors.forename: Huub J M
authors.initials: HJ
authors.lastname: de Groot