Efficient Photocatalytic Hydrogen Evolution over TiO2-X Mesoporous Spheres-ZnO Nanorods Heterojunction

Abstract

Photocatalytic water splitting into hydrogen is regarded as one of the key solutions to the deterioration of the global environment and energy. Due to the significantly reduced grain boundaries, ZnO nanorods facilitate a fast electron transfer through their smooth tunnels and are well suited as a photocatalyst. However, the photocatalytic hydrogen evolution performance of pristine ZnO nanorods is still low due to the high recombination rate of photogenerated electron-hole pairs and the less light absorption. Here, a novel structure about black ZnO nanorods (NRs)/TiO2-X mesoporous spheres (MSs) heterojunction has been prepared and the photocatalytic hydrogen evolution performance has been explored. The photocatalytic activity test results showed that ZnO NRs/TiO2-X MSs exhibited higher catalytic activity than ZnO NRs for hydrogen production. Compared to the pure ZnO NRs photoanode, the photocurrent of ZnO NRs/TiO2-X MSs heterojunction photoanode could reach 0.41 mA/cm2 in view of the expanding spectral response region and effective inhibition of e−/h+ recombination at the same condition. Using a relatively integrated experimental investigation and mechanism analysis, we scrutinized that after being treated with NaBH4, TiO2 MSs introduce oxygen vacancies expanding the photocatalytic activity of pure TiO2, and improving conductivity and charge transport capabilities through coating on ZnO NRs. More importantly, the results provide a promising approach in the NRs/MSs composite structure serving as photoanodes for photocatalytic hydrogen production.

Efficient Doping Induced by Charge Transfer at the Hetero-Interface to Enhance Photocatalytic Performance

“…Graphene oxide (GO) and all of the other analytical reagents were purchased from Aladdin Industrial Corporation (Shanghai, China) and used without further purification. Black TiO 2– X mesoporous spheres (MS) were synthesized according to a previous study . TiO 2– X /BiOI/GO (designated as X TB@ Y G, TiO 2– X = T, BiOI = B, @GO = @G) was synthesized via a one-step hydrothermal method as follows.…”

“…Black TiO 2−X mesoporous spheres (MS) were synthesized according to a previous study. 37 TiO 2−X /BiOI/GO (designated as XTB@YG, TiO 2−X = T, BiOI = B, @GO = @G) was synthesized via a one-step hydrothermal method as follows. Briefly, 10 mmol of Bi(NO 3 ) 3 •5H 2 O and 20 mmol of NaI were dissolved in 40 mL of glycol and 20 mL of deionized water, respectively, to form a homogeneous solution by magnetic stirring.…”

Influence of O2 Flow Rate on the Properties of Ga2O3 Growth by RF Magnetron Sputtering

“…However, hardly any reports about the effect of the O 2 flow rate at fixed Ar flow rate on the structure and optical properties of β-Ga 2 O 3 thin films deposited by the reactive RF magnetron sputter. Since oxygen deficiency in the growth process can induce oxygen vacancies in Oxide semiconductor materials, oxygen vacancies affect the optical and electrical properties of oxide semiconductor films [ 20 , 21 , 22 , 23 , 24 ]. Therefore, it is of great significance to study the effect of the O 2 flow rate on the characteristics of Ga 2 O 3 thin films deposited by RF magnetron sputtering.…”

Broadband Detection Based on 2D Bi2Se3/ZnO Nanowire Heterojunction

“…In addition, the merits of being low-cost, non-toxic and easy to prepare make it more attractive to be investigated [9][10][11]. Various morphologies of ZnO have been prepared during years of research, such as nanoparticle, nanowire, nanotube, nanofilm, and nanosheet [12][13][14][15]. The morphology with different dimensions has different characteristics.…”