Effects of hydrothermal temperature on the morphology and photoelectrocatalytic performance of TiO₂-based nanomaterials photoelectrode

Abstract

TiO 2 -based nanomaterials (BNMs) photoelectrode was successfully synthesized via a facile and controllable hydrothermal procedure. The as-prepared TiO 2 -BNMs photoelectrode was characterized by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The resulting TiO 2 -BNMs samples assembled by different morphologies were obtained through changing hydrothermal temperature that were: (i) One-dimensional (relative to nanosheets) nanobelts at 140 ○ C, (ii) two-dimensional nanosheets at 160-180 ○ C and (iii) three-dimensional network nanowires at 200-220 ○ C. Structural investigation of the obtained nanomaterials revealed that the content of anatase increased as increasing the apparent dimensionality of the materials. The photoelectrochemical performance of TiO 2 -BNMs photoelectrode was elucidated by comparative investigation on the electron transport and electron-hole (e À /h þ ) recombination in TiO 2 -BNMs sample with typically morphology. The photoelectrochemical performance of the TiO 2 -BNMs sample was obviously dependent on the morphology. Compared to the nanobelts and the network nanowires structure, the two-dimensional nanosheets displayed the more effective photogenerated electron transfer and reduced electron-hole recombination rate. Moreover, two-dimensional nanosheets had significantly enhanced photoelectrocatalytic efficiency for degradation of methyl orange (MO).TiO 2 -based nanomaterials (BNMs) is an important semiconductor material that is used in the fields of solar energy conversion, 1 water splitting, 2 waste water treatment, 3 and other application 4 due to their outstanding physicochemical property. Generally, the performance of the TiO 2 -BNMs is strongly dependent on its crystallographic phase, morphology and other properties. 5-8 Among all the TiO 2 crystallographic phase, anatase has been proved to be the most excellent applications in photocatalysts. 9 Another important factor is the morphology of TiO 2 -BNMs which affects not only on the adsorption and diffusion of pollutants but also on the transfer and separation of the photoinduced charge carriers. 5,10 Therefore, the crystallographic phase and the morphology of TiO 2 -BNMs are the key aspects for obtaining functional materials with excellent catalysis performances.In recent years, TiO 2 -BNMs have been successfully produced by a variety of methods, including sol-gel method, 11 physical and chemical vapor deposition, 12,13 electrochemical anodic oxidization 14 and hydrothermal method. 15 Among these methods mentioned above, hydrothermal method has been attracting much attention due to its facile procedures and controllable morphologies. Interestingly, not only onedimensional nanowires but also two-dimensional nanosheets or three-dimensional nanomaterials arrays can be grown on the Ti substrate by this approach. Recently, Shao et al. 16 prepared several kinds of one-dimensional TiO 2 nanostructures including nanorod arrays, nanobelt arrays, and § Corresponding author.

Preparation and characterization of TiO 2 -based nanosheets for photocatalytic degradation of acetylsalicylic acid: Influence of calcination temperature

“…The cleaning process of the Ti foils was according to our previous studies [35]. In detail, the cleaned Ti foils were transferred into a stainless para-polyphenyl(PPL)-lined autoclaves of 50mL inner volume, which were filled with 20mL of 1M NaOH aqueous solution.…”

Hydrothermal synthesis of Fe2O3/ZnO heterojunction photoanode for photoelectrochemical water splitting

“…1 Many metal oxides have been widely used in the process of the PEC water splitting, like TiO 2 , Fe 2 O 3 , zinc oxide (ZnO) and so on. [2][3][4] Especially, α-Fe 2 O 3 has been significantly investigated in-depth due to its various advantaged properties, such as chemical stability, erosion resistance, non-toxicity and high photocatalytic activity. 5 However, the photoelectric conversion efficiency of single α-Fe 2 O 3 is low 6 resulting from its short lifetime of photogenerated charge carriers, limited hole diffusion length, and poor mobility of charge carriers.…”