Photocatalytic Hydrogen Generation Of Surface-Modified TiO₂

Changes need to be made to our energy consumption structure and they should be made very soon,on the grounds that the overconsumption of fossil fuels has been taking a heavy toll on many species on Earth.Photocatalytic hydrogen generation has gained considerable attention in this regard for being green.TiO₂ being one of the earliest photocatalysts still have room to surprise us with better photocatalytic activity,like the emerge of black TiO₂,which possesses a much narrower bandgap than pristine TiO₂ and other valuable qualities?depending on how to prepare it?.Therefore,the focus of this dissertation is to improve TiO₂ through surface modification.There were two steps here to modify the surface of anatase TiO₂-black TiO₂ growth on anatase TiO₂ and subsequent Au nanoparticles decoration on black TiO₂/anatase TiO₂.Disordered black TiO₂ growth on anatase TiO₂ was achieved by atomic layer deposition method,which allows black TiO₂ to grow in a facile but highly controllable way.We are able to manipulate the UV-Vis absorption of black TiO₂ by changing the parameters of atomic layer deposition.And Ti3+ and hydroxyl group were found in black TiO₂/anatase TiO₂.Au decoration was carried out by simple deposition precipitation with Na OH.We found that the size of Au nanoparticle deposited on black TiO₂/anatase TiO₂ varies with the amount of Au added.Furthermore,the thickness of black TiO₂ has an impact on the photocatalytic hydrogen generation of black TiO₂/anatase TiO₂,which can generate hydrogen about 14-fold higher than that of pristine TiO₂ by adjusting the thickness of black TiO₂,indicating that preferable amount of defects can be obtained by changing the thickness of black TiO₂ through atomic layer deposition.Additionally,the amount of Au added in Au-black TiO₂/anatase TiO₂ affects its photocatalytic hydrogen generation.By varying the addition of Au,Au-black TiO₂/anatase TiO₂ showed a hydrogen generation rate of about 17-fold higher than that of pristine TiO₂,and 1.2 times higher than that of black TiO₂/anatase TiO₂.