Experimental investigation of photocatalytic hydrogen production with boron-doped TiO2 and multi-walled carbon nanotubes-TiO2

Abstract

This thesis investigates photocatalytic hydrogen production by performing an experimental study using a small-scale photochemical cell which splits water to hydrogen and oxygen by UV light irradiated boron-doped TiO2 and carbon nanotube-TiO2 semiconductor photoelectrodes. The average current densities generated under potentiostatic scan for uncoated stainless steel, boron-doped TiO2 and carbon nanotube-TiO2 working electrodes are observed to be 112.51 mA /cm2, 128.43 mA /cm2, and 164.73 mA /cm2 under UV light respectively. Although amount of hydrogen produced by carbon nanotube-TiO2 is higher than boron-doped TiO2, boron-doped TiO2 has the maximum energy and exergy efficiencies. Moreover, in this study, alternative reactor designs are proposed and simulated on COMSOL Multiphysics software in order to improve the flow of the hydrogen bubbles inside of the reactor. The simulation results showed that the amount of hydrogen at the beginning for the three designs 1.19 𝑐𝑚2 drops to 0.078 𝑐𝑚2 which shows 32.5% improvement and 0.0581 𝑐𝑚2 which represents 34.9% improvement in hydrogen released compared to the base design for first and second proposed designs respectively.