Hussein Alrobei
University of South Florida, USA
Title: a-hematite-molybdenum disulfide and polyhexylthiophene (RRPHTh)- nanodiamond (ND) electrodes for photoelectrochemical applications
Biography
Biography: Hussein Alrobei
Abstract
The alpha (a)-hematite (Fe2O3) nanomaterial is attractive due to its band gap, chemical robustness, availability in the nature and excellent photoelectrochemical (PEC) properties to split water into oxygen and hydrogen. However, the a-Fe2O3 suffers from low conductivity, slow surface kinetic, low carrier diffusion and greater electron-hole combination. The electronic properties such as carrier mobility and diffusion of a-Fe2O3 can be improved through doping, synthesis of composite material or formation of structured films. Recently, 2D-molybdenum disulfide (MoS2) has shown interesting photocatalytic activity due to its bonding, chemical composition, doping and nanoparticles grown on other 2D-film. Recently, our group has studied photoelectrochemical properties of hybrid film of regioregular poly (3-hexylthiophene-2, 5-diyl) (P3HT) with nanodiamond as well as P3HT-MoS2. In the present study, we have studied photoelectrochemical properties of polyhexylthiophene (RRPHTh)-nanodiamond (ND) and a-Fe2O3-MoS2 nanocomposite based electrodes films. The photoelectrochemical properties of a-Fe2O3-MoS2 as n-type and ND-RRPHTh as p-type electrodes in photoelectrochemical cell in various electrodes have been studied. We have obtained ~3 to 4 times higher photocurrent and energy conversion efficiencies than the parent electrode based photoelectrochemical cell. We have synthesized nanocomposite a-Fe2O3-MoS2 using sol-gel technique. The nanocomposite a-Fe2O3-MoS2 as well as ND-RRPHTh films were characterized using SEM, X-ray diffraction, UV-vis, FTIR and Raman techniques. The electrochemical techniques were used to understand the photocurrent in electrode/electrolyte interface of a-Fe2O3-MoS2 as well as ND-RRPHTh films in both acid base based electrolyte. The a-Fe2O3-MoS2 and ND-RRPHTh electrodes reveal improved production of hydrogen compared to a-Fe2O3 and aluminum doped a-Fe2O3 and MoS2 doped a-Fe2O3 nanostructured films. The band structure has been used to understand the mechanism of photoelectrochemical water splitting in p-n types based photoelectrochemical cell.