Title: Tungsten oxide-reduced graphene oxide composites for photoelectrochemical water splitting

Abstract

Photo Electro Chemical (PEC) water splitting is the latest technology to produce safe hydrogen and electricity by using sun light. This technology permits to split water in to its basic constituents i.e. hydrogen and oxygen. Hydrogen being highly flammable gas can be used as fuel in different sectors of life to overcome the energy needs. Oxygen gas can be utilized by the human beings for respiration. The process resembles with photosynthesis of plants to prepare food in the presence of sun light. Tungsten Oxide (WO3) and reduced Graphene Oxide (rGO) were the materials used under different compositions to fabricate PEC cells for production of safe electricity. The low band gap of tungsten oxide (WO3) enables it as a suitable candidate for PEC water splitting. Graphene Oxide (GO) is a material having extra thin sheets and a very large surface area with extreme electrical conductivity. GO has been synthesized by using modified Hummer’s method. Later on hydrothermal reduction of GO gives rGO. WO3–rGO composites of different ratios have been prepared hydrothermally and then coated on indium tin oxide coated glass to make electrodes for water splitting. Renewable energy technologies have their immense scope after the scarcity of fossil fuels. Various characterization techniques such as UV–visible, Diffusion Reflectance Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy and Linear Sweep Voltammetry were used to study the absorbance/reflectance, structure, morphology, and optical/electrical properties of prepared nanostructures. In addition, WO3 particles were distributed on the strong sheets of rGO randomly. The IV-measurements were taken of WO3 / rGO electrodes under dark environment (very minor current~250 nA) by using LSV. The electrodes exhibit maximum of ~ 450 μA under dark environment, while photocurrent initiates from 1.0 mA to 3.2 mA under artificial sunlight. That is convincingly an exceptional result in the field of PEC cells.

Biography

Shahzad Munir Ansari is a PhD fellow of Federal Urdu University of Arts Science and Technology, Islamabad, Pakistan in Applied Physics Department. He earned Degree of Masters of Philosophy in Applied Physics with specialization in the field of renewable energy technology mainly focused on “Novel Materials for Energy Applications” from the same university. Because of the remarkable properties of Graphene, his research is focused on it with its different compositions. He served as Researcher at National Centre for Physics Islamabad Pakistan for two years. He has hands on experience of Synthesis of Graphene / Graphene Oxide / reduced Graphene Oxide and their different compositions with metal oxides and other semiconductor materials for various energy applications. He has published two research articles in the well-known international scientific journals. Recently prepared Copper Plated-Graphene Based Ultra Capacitors and their testing is in progress. In the meanwhile research and development is going on Graphene Batteries.