Photoelectrochemical zero bias hydrogen generation has been achieved with self-assembled nanoporous anatase type TiO2 (SANAT) photoelectrode and chemical bias. The SANAT fabricated using halogen free conventional electrolytes by anodization exhibits more than 2 times superior performance to rutile single crystal electrodes in photoelectrolysis of water. The chemical bias assisted cell consists of two separate compartments connected by a liquid junction. The SANAT anode is immersed in alkaline electrolyte, Pt cathode is in acidic electrolyte. The use of electrolytes of two different pH values produces a chemical bias of 0.059 ∆pH V due to the proton concentration gradient. Under zero bias condition, photocurrent sufficient for photolysis of water was observed. Hydrogen evolution was visible at counter electrode without the application of any external voltage. We call this system fuel type photoelectrochemical zero bias hydrogen generation or water splitting.

A Compact Planar Magnetron Plasma Sputtering Deposition Device (CPM-PSDD) has been used to deposit TiO2 on silicon, glass and cotton cloth. An 80 mm diameter Ti target was placed at the cathode and was sputtered by argon-oxygen plasma with 10-20 mA discharge current and -300 V to -450 V discharge potential. Reactive oxygen gas fed into the system at 13:1 Ar:O2 sccm ratio for the deposition durations between one to four hours. The deposited films exhibited both anatase and rutile phases. Cotton cloths were dipped in methyl blue to evaluate the photocatalytic activity of the film.

The SrZnO2 thin films were fabricated by using laser ablation method. The films were annealed after deposition in order to improve the crystallinity. Water splitting experiments were carried out and hydrogen production over the SrZnO2 thin films were confirmed with no applied bias. The band gap of SrZnO2 was 3.41 eV which is 0.15 eV larger than that of ZnO. It suggests that the band gap was increased by doping Sr to ZnO, and the reducibility was improved. As a result, the rate of photocatalytic hydrogen production over the SrZnO2 was increased compared to ZnO.

The aim of this research study is to produce high quality TiO2 nanotube arrays. It is shown that sol-gel electrophoresis is a suitable one to obtain vast-area TiO2 nanotube arrays when nanoporous alumina templates are used. To fabricate TiO2 nanotube arrays, alumina templates were produced via a two-step anodizing by a homemade anodizing cell using high purity phosphoric acid as the electrolyte with aluminum and platinum as electrodes. The semiconductor behavior of these templates can also be employed when producing conducting substrates for the grown TiO2 nanotubes. Stabilized titanium sol was prepared by modified hydrolysis of the titanium precursor using acetic acid. In order to produce TiO2 nanotube arrays, the template pores were filled with the precursor sol by applying a DC electric field. Then, the filled template was heat treated to crystallize the desired TiO2 phase. Scanning electron microscopy of TiO2 nanotube arrays showed that the nanotubes have been deposited in the channels of the nanoporous alumina template. X-ray diffraction data confirmed phase structure and composition of TiO2 nanotube arrays after heat treatment. To reach pure anatase phase, the samples were heated at 320°C and 400°C for two hours. To obtain pure rutile phase, the samples were heated at 320°C and 750°C for two hours.