Research On Photoelectronic Properties Of B-Doped And N, B-Codoped Tio₂

Energy and environment are significant problems that will influence social development both present and in the future, thus it is urgent to develop new energy and manage environment problems. Actually, photochemical is the one of the most promising way to deal with the energy and environment problem. In this experiment, B-doped TiO₂ was synthesized by a direct hydrolyzation of n-tetrabutyl titanate, and was treated by hydro-thermal synthesis. This experiment also explores that B-doping can introduce Ti-O-B bond into TiO₂ and improve the optical properties of the powders. The B-doped TiO₂ was characterized by XRD, SEM/TEM, XPS, FT-IR and UV-vis Spectra. Moreover, this experiment assembled B-doped TiO₂ powder into dye-sensitized solar cells and optimized light anode preparation technic. The experiment results showed that doped B existed in the form of Ti-O-B and B-O-B, and as the doped B atomic ratio increased, the battery's short circuit photocurrent increased and the open-circuit photovoltage decreased. Meanwhile, compared with the 2.00% conversion efficiency of the DSSC prepared by TiO₂, conversion efficiency of B-doped TiO₂ battery improved, with the highest point 2.39%. The photocatalytic activity of as-prepared B-doped TiO₂ was determined by photodegradation of RhB under simulated solar light, and it showed an excellent photocatalytic performance. Compared to non-doped TiO₂, the apparent rate constant of the B-doped TiO₂ was 2 times as that of non-doped TiO₂. The result illustrate that B-doping could enhance the photocatalytic activity of TiO₂.This experiment shows that the B-doping can narrow the band gap of TiO₂ powder and widen the absorption spectrum (able to absorb the visible light) with literature report. B element and N element work well in cooperation without reciprocal inhibition. Hence, this experiment prepared B, N-codoped TiO₂ powder through self-designed GS (Gas-Solid System) N-doping instrument. Surface topography, phase composition, absorption spectrum, doped-B atom ratio and state of B, N-codoped TiO₂ are characterized by various methods. The results show that as the temperature increases, the reaction pressure (NH3), reaction time and doped N increase, conversely, doped N decreases. As Ti-O-B bonds increase, doped N ratio increases, optical property of DSSC battery assembled by B, N-codoped TiO₂ powder increases largely, and most of the conversion efficiency are above 3.00%, with the highest point 4.04%.