Construction Of TiO₂ Nanoarray Composite Photoelectrode And Its Photoelectrochemical Properties

The construction of nanomaterial composite system has the characteristics of simplicity,economy and high efficiency in promoting the separation of photogenerated electron holes,so it has been widely concerned by people.In order to improve the photocatalytic performance of semiconductor materials,surface modification of semiconductor materials is carried out to construct schottky barrier and realize the effective separation of photogenerated electrons.In order to improve the photocatalytic performance of semiconductor materials.People are focus on surface modification of semiconductor materials,which is an effective method to construct Schottky barrier for separation of photogenerated electrons.At present,the methods of surface modification mainly include precious metal deposition and semiconductor recombination.Unlike the principle of photocatalysis,photoelectrocatalysis?PEC?can be applied bias to generate electric field,which can separate electrons and holes more efficiently.In addition,the photoelectrocatalysis can generate electrical signals.Therefore,photoelectrocatalysis can be used not only to environmental remediation and energy production,but also in the field of sensors.Titanium dioxide?Ti O₂?has unique properties,such as high stability,high selectivity,high sensitivity and low cost,so it has attracted attention in the field of photoelectrocacatalysis.However,electrons and holes are easy to recombination,which is one of the disadvantages of titanium dioxide,and this recombination seriously reduces the photoelectrocatalysis activity of Ti O₂.In this paper,Ti O₂nanotube arrays?TNTAs?and nanorod arrays?TNRs?with different morphologies were prepared by anodic oxidation and hydrothermal methods.Subsequently,?1?Au nanoparticles?Au NPs?was decorated on Ti O₂NTAs to construct a flexible three-dimensional Au@Ti O₂nanotube array,and studied the effect of bending degree on its PEC biosensing performance.?2?The core-shell nanorod arrays?Mo Se₂@Ti O₂NRs?were constructed by using Mo Se₂as semiconductor materials decorate on Ti O₂NRs,and the effect of the presence of Mo Se₂on the photoelectrocatalytic preparation of H₂O₂by Ti O₂was studied.The experimental results show that:?1?The flexible Ti mesh substrate endows Au@Ti O₂with intrinsically collapsible nature,which insures its PEC biosensing performance almost unaffected under indirect light irradiation and serious tensile strains.Moreover,the asymmetric Au@Ti O₂system successfully forms the energy barrier which efficiently suppress the combination of electron-hole pairs,thus greatly increasing the photogenerated holes'lifetime.Au@Ti O₂exhibited excellent photoelectric activity and selectivity than that of Ti O₂without gold nanoparticles.Moreover,the holes and their further produced hydroxyl radicals?·OH?selectively recognize and oxidize glucose,which have been further proven by ESR technology.The significance of this experiment may help stimulate a lot of research on flexible materials to promote the implementation of smart PEC sensing devices in practical.?2?Mo Se₂can be decorated on Ti O₂NRs by hydrothermal method.The matching of band positions resulted in the formation of heterojunction between Ti O₂and Mo Se₂,which is an effective way to promote the separation of electron-hole pairs.The production of H₂O₂by Mo Se₂@Ti O₂was much higher than that of Ti O₂.This result means that Mo Se₂is an important factor for Ti O₂to achieve high H₂O₂production,which is an effective way to inhibit the recombination of Ti O₂electron-holes pairs.