title: NiS1.97: A New Efficient Water Oxidation Catalyst for Photoelectrochemical Hydrogen Generation.
abstract: NiS1.97, a sulfur-deficient dichalcogenide, in nanoscale form, is shown to be a unique and efficient photoelectrochemical (PEC) catalyst for H2 generation by water splitting. Phase pure NiS1.97 nanomaterial is obtained by converting nickel oxide into sulfide by controlled sulfurization method, which is otherwise difficult to establish. The defect states (sulfur vacancies) in this material increase the carrier density and in turn lead to favorable band line-up with respect to redox potential of water, rendering it to be an effective photoelectrochemical catalyst. The material exhibits a remarkable PEC performance of 1.25 mA/cm(2) vs NHE at 0.68 V in neutral pH, which is almost 1000 times superior as compared with that of the stoichiometric phase of NiS2. The latter is well-known to be a cocatalyst but not as a primary PEC catalyst.
authors: Physical and Materials Chemistry Division, National Chemical Laboratory , Pune 411008, India.|Academy of Scientific and Innovative Research, Anusandhan Bhawan , 2 Rafi Marg, New Delhi 110001, India.
authors: Reshma
authors: R
authors: Bhosale
authors: Physical and Materials Chemistry Division, National Chemical Laboratory , Pune 411008, India.
authors: Sarika
authors: S
authors: Kelkar
authors: Indian Institute of Science Education and Research , Dr. Homi Bhabha Road, Pashan, Pune 411008, India.
authors: Golu
authors: G
authors: Parte
authors: Department of Physics and National Centre for Nanosciences & Nanotechnology, University of Mumbai , Vidyanagri, Santacruz (E), Mumbai 400098, India.
authors: Rohan
authors: R
authors: Fernandes
authors: Department of Physics and National Centre for Nanosciences & Nanotechnology, University of Mumbai , Vidyanagri, Santacruz (E), Mumbai 400098, India.
authors: Dushyant
authors: D
authors: Kothari
authors: Physical and Materials Chemistry Division, National Chemical Laboratory , Pune 411008, India.|Academy of Scientific and Innovative Research, Anusandhan Bhawan , 2 Rafi Marg, New Delhi 110001, India.|Indian Institute of Science Education and Research , Dr. Homi Bhabha Road, Pashan, Pune 411008, India.
authors: Satishchandra
authors: S
authors: Ogale
keywords: Faradaic efficiency; NiS1.97; dichlacogenide; hydrogen generation; nonstoichiometric; photoelectrochemical catalyst; sulfurization