Research On Tio₂ Nanorods And Tio₂ Nanotubes As The Anode Material In Hydrogen Production From Photoelectrochemical Water Splitting

As a clean and high efficiency energy carrier,hydrogen has an important position in new energy field.To get hydrogen,other energies need to be consumed.One of the focus of current research on hydrogen energy is to utilize solar energy.Photoelectrochemical?PEC?water splitting becomes one of the most important topic.In this work,TiO₂ nano materials,were applied as the photoanode of PEC water splitting.The effect of annealing atmosphere,such as O₂,air,N₂,H₂ and Ar,on the activity of the TiO₂ anode in PEC water splitting are systematically examined.The X-ray photoelectron spectroscopy?XPS?,photoluminescence spectroscopy?PL?results show that the TiO₂ nanorods annealed under different atmospheres have different flat band potentials and the annealing atmosphere has a significant impact on the separation of the surface photoelectrons and holes.Annealing in innert atmospheres?especially in Ar?are more conducive to the separation of the photogenerated carriers and the transfer of the charges.Compared to the sample annealed in O₂,the photocurrent density of the sample annealed in Ar increases from 0.402 mA/cm² to0.762 mA/cm² at 0 V?vs.Ag/AgCl?,having 89.5%improvement.A new method of double anode reduction to deal with TiO₂ nanotubes is firstly designed,that is,hydrogenation treatment of Ti O₂ nanotubes to get black TiO₂ by double anode reduction.Dealing with TiO₂ nanotubes by the method of double anode reduction can reach the highest PEC activity at 2.050mA/cm²,which is about 3 times high as the pure TiO₂ nanotubes.In this work,the process of double anode reduction to deal with TiO₂ nanotubes in ethylene glycol system is carried out.It is concluded that the improvement of the activity of PEC water splitting is due to the synergism of C,N co-doping and the hydrogenation treatment of TiO₂ nanotubes.The treatment of double anode reduction and the dipping treatment of TiO₂ nanotubes by C₃N₄ and NaH₂PO₄ are compared.The characterizations of Ultraviolet and visible spectrophotometry?UV-Vis?and PL show that the double-anode reduction treatment of TiO₂ nanotubes not only enhances the ability of UV-Vis light absorption,but also improves the separation efficiency of photogenerated carriers.The mechanism of double anode reduction realizes a significant improvement of PEC water splitting,what's more,it is simple and easy to get blackened TiO₂ nanotubes.The method of double anode reduction is of great significance to promote the process of electrode material hydrogenation.