Preparation Of Titanate Nanotube Films And Their Photocatalytic Properties For Hydrogen Production From Water Splitting

Nanotube have drawn extraordinary attention due to their high specific surface area.The tubular structure is easy to synthesize nanotube composite materials, which canimprove photocatalytic activities of catalysts significantly. Na₂Ti₃O₇nanotube films andSrTiO₃nanotubes array were prepared by combining of hydrothermal method andanodic oxidation, and then precious metals were assembled to titanate nanotube arraysto improve the activities of catalysts. The morphologies, structures, compositions ofcatalysts and optical property were characterized by SEM, EDS, XRD,DRS and XPSanalysis. And the photocatalytic activities of catalysts were tested by photocatalytichydrogen evolution from water.Firstly, Na₂Ti₃O₇nanotube films were prepared by combining of hydrothermalmethod.Then In₂S₃/Na₂Ti₃O₇nanotube films were synthesized by precipitationreaction.In order to increase the catalytic activity of material,Pt was been couplingonIn₂S₃/Na₂Ti₃O₇nanotube films.The analysis show that In₂S₃was charged on theNa₂Ti₃O₇nanotubes film, and In₂S₃Optical absorption properties of Na₂Ti₃O₇nanotubescan be expanded to the visible light regions, In₂S₃–Na₂Ti₃O₇might absorb visible light.Visible light catalytic properties of In₂S₃–Na₂Ti₃O₇nanotube films obtained in differentconcentration of InCl₃solution were studied.Research results show that theconcentration of0.1M InCl₃has the highest catalytic efficiency, and after load of Pt,hydrogen efficiency is significantly improved.The second,TiO₂nanotube arrays were prepared by the anodization of metallic Tifoil. Then SrTiO₃nanotube arrays were synthesized by hydrothermal method. Amongthem, the samples maintained good morphology which were obtained by hydrothermaltreatment of TiO₂for2h, the TiO₂nanotube arrays were prepared in glycol/H2O/NH4Fbased electrolyte.In order to improve the photocatalytic activities of SrTiO₃nanotubearrays, the Ag/Ag/SrTiO₃nanotube arrays were obtained by immersion-illuminationmethod.SEM analysis shows that Ag/AgI nanoparticles can be load on SrTiO₃nanotubearrays by this way,and the Ag/AgI particle size and amount were increased significantlywith the concentration of AgNO₃was increased. XRD and XPS analysis shows that the nanoparticles contain Ag and AgI two particles.In the test of photocatalytic hydrogenevolution from water, the effect of AgNO₃concentration on photocatalytic performancewas studied. The result shows that Ag/Ag/SrTiO₃nanotube arrays obtained in0.1MAgNO₃have higher hydrogen production rate. The hydrogen production rate ofAg/Ag/SrTiO₃nanotube arrays was4.11mmol/m2/h.In addition, the Au/SrTiO₃nanotube arrays were prepared by hydrothermaltreatment method. The SEM and EDS analysis show the amount and size of Audeposited on the nanotube arrays increases with increasing the reaction time. Moreover,XRD analysis shows that characteristic peak of Au. In the test of photocatalytichydrogen evolution from water, the effect of PVP and reaction time on photocatalyticperformance was studied.The result shows that with the hydrothermal time and amountof PVP were increased, photocatalytic activity showed a trend of decrease afterincrease.