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[Display omitted] • A novel Mo, C co-doped TiO 2 was synthesized by combination of sol–gel synthesis and low-temperature calcination. • Such MO, C-TiO 2 exhibited unique electronic structure to facilitate the formation of oxygen vacancies. • Such Mo, C-TiO 2 delivered remarkable NH 3 removal efficiency and stability under visible light irradiation. • The N 2 H 4 mechanism of the NH 3 photocatalytic oxidation was firstly reported to favor the production of N 2. • DRIFTS and DFT results demonstrated the gradual reaction of NH 3 adsorbed on Mo atoms with O 2 to form N 2 and H 2 O. Ammonia gas (NH 3) is a notorious malodorous pollutant with detrimental effects on environment and human health. Removing NH 3 through photocatalytic oxidation remains a challenging task due to unclear reaction mechanisms. In this study, DFT simulation results revealed that C doped TiO 2 could extend the photo-response range to the visible region, but the introduction of deep impurity levels was found to accelerate photogenerated carrier recombination. Fortunately, the rational doping of Mo was found to mitigate this negative effect. Accordingly, Mo, C co-doped TiO 2 was synthesized via a facile low-temperature calcination process, resulting in unique band structure that enhanced the photocatalytic oxidation of NH 3. Notably, in-situ DRIFTS and DFT results demonstrated that the gradual reaction of NH 3 adsorbed on Mo atoms with oxygen species through the N 2 H 4 mechanism, promoting the formation of N 2. These findings offer insights into the design of efficient photocatalysts for NH 3 removal under visible light, and present a promising technology for indoor air pollution control. [ABSTRACT FROM AUTHOR]

Electrocatalytic CO 2 reduction (CO 2 ER) to produce formic acid (HCOOH) would be an attractive means for carbon neutralization. In order to realize efficient CO 2 ER and economical conversion of CO 2 , the applying of metal active sites on surface of semiconductor has emerged as a promising strategy. Herein, we report the preparation of alkaline modified TiO 2 nanowires (NWs) as the substrate for Au photodeposition. The as-fabricated Au/TiO 2 NWs exhibits high activity and selectivity towards HCOOH production compared with traditional catalysts. The key factors including deposition time, solution, and etc. And their effects on CO 2 ER performance have been systematically investigated. At −0.8 V vs RHE, the Faraday efficiency of the HCOOH can reach to 86.49 %, while the current density is 15.94 mA cm−2. In addition, Au/TiO 2 NWs also exhibited good stability after 18 h electrocatalytic CO 2 RR under the voltage of −0.8 V vs RHE. Electrochemical tests indicated that Au/TiO 2 NWs process favorable intrinsic electrochemical properties, high ESCA and accelerating charge transfer process make Au/TiO 2 NWs obtain abundant active sites and kinetically favorable. This work provides a convenient fabrication strategy of Au/TiO 2 based catalyst, which can guide the design and modification of gold for CO 2 ER into formic acid. [Display omitted] • A low-cost fabrication strategy of self-supported Au/TiO 2 from alkaline modified TiO 2 nanowires and photodeposited Au. • The photodeposition conditions were optimized to tune the CO 2 reduction active sites on Au/TiO 2. • Metal-support interaction between Au and TiO 2 modulate the electronic structure and promote CO 2 reduction. • Prepared Au/TiO 2 NWs efficient catalytic CO 2 conversion to formic acid (FE HCOOH = 86.49 %, @−0.8 V vs. RHE). [ABSTRACT FROM AUTHOR]

[Display omitted] • Light absorption range of TiO 2 /ACF broadens from the UV region to the visible region. • Cumulative hydrogen production with TiO 2 /ACF addition was nearly doubled. • The addition of TiO 2 /ACF shortened the photo-fermentation period from 84 h to 48 h. • TiO 2 /ACF promoted metabolic pathway of HAU-M1 to convert acetate and butyrate to H 2. • Characterization results after fermentation confirmed the reusability of TiO 2 /ACF. In this study, titanium dioxide/activated carbon fiber (TiO 2 /ACF) was synthesized by liquid-phase deposition method and the effect of TiO 2 /ACF on the performance of photo-fermentation biohydrogen production (PFHP) from corn stover under visible light catalysis was discussed. Results show the maximum cumulative hydrogen yield (CHY) obtained under the optimal conditions was 74.0 ± 1.3 mL/g TS with TiO 2 /ACF addition of 100 mg/L, which was twice that without TiO 2 /ACF addition (36.9 ± 1.0 mL/g TS). Initial pH value had the most significant effect on CHY. The addition of TiO 2 /ACF promoted the metabolic pathway of nitrogenase to reduce H+ produced by consuming acetic acid and butyric acid to hydrogen, and also shortened the photo-fermentation period. By scanning electron microscopy and X-ray diffraction analysis, the morphology and phase structure of TiO 2 /ACF after PFHP did not change significantly. This study laid the foundation for the reuse of TiO 2 and its practical application in PFHP. [ABSTRACT FROM AUTHOR]

The SiO 2 –TiO 2 superhydrophilic coatings with photocatalytic activity via heat curing over a low temperature of 100 ℃ were fabricated without a high-temperature calcination process. The effects of the composite ratio of SiO 2 and TiO 2 on the stability of the sols, different treatment processes on the crystalline morphology of TiO 2 , and different solid contents of the sols on the coating properties were investigated. The surface morphology, optical properties and mechanical properties of the coatings were characterised by a water contact angle (WCA) analyser, UV spectroscopy, scanning electron microscopy (SEM) and multiple functional tests. The experimental results demonstrated that the SiO 2 –TiO 2 coating featuring both the intrinsic hydrophilicity of SiO 2 and photophilicity of TiO 2 had the WCA up to 3.5° and exhibited good photocatalytic, self-cleaning, anti-fogging, and mechanical properties. [Display omitted] • Low temperature induced crystallisation of TiO 2 for photocatalytic properties of the coating. • The superhydrophilic coating was produced by combining the intrinsic hydrophilicity of SiO 2 and the photophilicity of TiO 2. • The superhydrophilic coating has good stain resistance and self-cleaning properties. [ABSTRACT FROM AUTHOR]