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Ruthenium (II) was firstly coordinated with 4,4′-dicarboxy-2,2′-bipyridine for 4,4′-dicarboxy-2,2′-bipyridine ruthenium and then bonded with g-C 3 N 4 (designated as RuC@g-C 3 N 4 ), and were finally loaded in TiO 2 (designated as RuC@g-C 3 N 4 /TiO 2 ) by the solvothermal method. The obtained ruthenium complexes sensitizing g-C 3 N 4 /TiO 2 hybrid exhibited high photocatalytic performance under the visible light irradiation. The morphologis of photocatalysts were characterized by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM) with element mapping and Brunauer-Emmett-Teller (BET). The compositional structure and chemical composition were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectra (FTIR). Photoluminescence (PL) spectra indicated the addition of the ruthenium complexes enhanced the photo-generated electron-hole separation and transport, and the photocatalytic activity was evaluated by degradation of Methyl Blue (MB) under visible light irradiation. The results suggest that the minor amounts of ruthenium complexes sensitizing can usefully improve the photocatalytic performance, and the optimal theory mass ratio of TiO 2 to RuC@g-C 3 N 4 of 12:1 presents the best catalytic performance, and it is nearly 1.9 times as high as the conventional reported optimal g-C 3 N 4 /TiO 2 hybrid with the same mass ratio of TiO 2 /g-C 3 N 4 of 12:1 under visible light irradiation. At the end of article, a possible photocatalytic mechanism was discussed based on the experimental results. [ABSTRACT FROM AUTHOR]

Non-force equilibrium on the surface of g-C3N4; carbonylation of tri-s-triazine units; photocatalytic degradation of methyl blue with the different mass ratio of TiO2/g-C3N4 hybrid under visible light irradiation. [Display omitted] In this study, a novel spherical TiO 2 /g-C 3 N 4 hybrid was obtained by facile solvothermal synthesis. The morphologies were characterized by field emission scanning electron microscope (FE-SEM) and transmission electron microscopy (TEM). The structural properties of TiO 2 /g-C 3 N 4 were analyzed by X-ray diffraction (XRD) and the (002) peak shifted slightly in g-C 3 N 4 revealed the effect of TiO 2 on the interlayer distance of g-C 3 N 4 due to the tight contact between TiO 2 and g-C 3 N. The chemical compositions of TiO 2 /g-C 3 N 4 were analyzed by Foutier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the tiny characteristics were deeply analyzed for exploring carbonylation of tri-s-triazine units due to TiO 2 as catalyzer. The thermal stability of TiO 2 /g-C 3 N 4 hybrid was carried out by thermogravimetric differential scanning calorimetry (TG-DSC), and the degradation temperatures of g-C 3 N 4 obviously decreased under TiO 2. UV–vis diffuse reflectance spectroscopy (DRS) was performed to investigate the absorption bandgap energy, while photoluminescence (PL) indicated the lower recombination of photo-generated charges for TiO 2 /g-C 3 N 4 hybrids. The photocatalytic activity and stability of the TiO 2 /g-C 3 N 4 hybrid was evaluated by degradation of Methyl Blue under visible light irradiation. The result indicated that the optimum mass ratio of TiO 2 /g-C 3 N 4 of 12:1 was 7.3 times, 12.5 times and 87.5 times as high as that of Degussa P25, nanosheet TiO 2 and powder g-C 3 N 4 , respectively, which exhibited an excellent photocatalytic performance. Recycling test of H 12-1 shows still quite a high catalytic performance after the continuous irradiation of 600 mins. At the end of article, a possible photocatalytic mechanism was discussed based on the experimental results. [ABSTRACT FROM AUTHOR]

The objective of this research was to develop a high-performance CO 2 adsorbent by a simple, cost-effective and environmental-friendly route based on amine hybrid aerogel. A new amine hybrid titania/silsesquioxane composite aerogel (AHTSA) was prepared by a one-pot sol-gel process followed by supercritical drying (SCD). The wet gel was obtained by orderly mixing all the reactants in a container without adding any catalyst. SCD was conducted without contaminant emission. Effects of amine loading and CO 2 concentration on pores structure and CO 2 adsorption performance of AHTSA were investigated. Higher amine loading leads to lower specific surface area and mesopore volume of AHTSA, due to the increase of large pores and diminishment of mesopores when increasing the amine loading. Resulting from the sharp decrease of the surface area, overdosing of the amine precursor negatively affects the surface amine content of AHTSA and thus reduces its CO 2 adsorption capacity. High CO 2 concentration favors the CO 2 adsorption capacity and rate as concentrated CO 2 favors the CO 2 diffusion in the pore space of the adsorbent, enhances the interaction between CO 2 and surface amine groups. The dry CO 2 adsorption capacity of AHTSA increases from 1.64, 4.19 to 6.66 mmol/g when the CO 2 concentration of the mixture gas varies from ∼400 ppm (air), 1% to 10%. Short adsorption halftime and high amine efficiency of AHTSA with different CO 2 concentrations reveal that AHTSA is a dynamic and effective adsorbent for CO 2 capture, even direct air capture. [ABSTRACT FROM AUTHOR]

The objective of this study is to develop a new low-cost, highly selective, and stable sorbent based pre-combustion CO 2 capture. A high surface area titanium oxide (TiO 2 ) prepared by a template method and amine modified TiO 2 (M-TiO 2 ) were investigated for CO 2 /CH 4 adsorption at conditions relevant to pre-combustion CO 2 capture. Single-component and binary CO 2 /CH 4 adsorption tests at different operating conditions were performed in a fixed bed adsorber. Experimental results show that the selectivity of TiO 2 for separation of CO 2 from CO 2 /CH 4 mixture can be significantly improved via amine modification. The selectivity of CO 2 over CH 4 for M-TiO 2 is enhanced to 22.1 at 333 K and 35 bar. Pure CO 2 or CH 4 can be obtained from the adsorber packed with M-TiO 2 through cyclic CO 2 /CH 4 mixture gas adsorption and desorption. The study indicates that, as a pre-combustion sorbent, the inexpensive mesoporous M-TiO 2 is not only capable and stable, but also easily regenerated without loss of capacity and selectivity. [ABSTRACT FROM AUTHOR]

Abstract: A novel method was developed to synthesize graphite oxide/TiO2 composites as a highly efficient photocatalyst by in situ depositing TiO2 nanoparticles on graphene oxide nano-sheets by a liquid phase deposition, followed by a calcination treatment at 200°C. The two-dimensional porous graphene oxide/TiO2 composites had specific surface area of 80m2 g−1 being considerably larger than that of P25 and the similarly prepared neat TiO2 particles without using graphene oxide. The composites exhibited excellent photocatalytic activity, being influenced by post-calcination temperature, graphene oxide content and solution pH. Under optimal conditions, the photo-oxidative degradation rate of methyl orange and the photo-reductive conversion rate of Cr(VI) over the composites were as high as 7.4 and 5.4 times that over P25, respectively. The excellent enhancing effect of graphene oxide nano-sheets on the photocatalytic properties of TiO2 was attributed to a thin two-dimensional sheet support, a large surface area and much increased adsorption capacity, and the strong electron transfer ability of the thermally reduced graphene oxide in the composite. [Copyright &y& Elsevier]

As a terrific hydrogen carrier, NH 3 can be wildly used as non-carbon gas fuel in energy area, because NH 3 can store a high density of H 2 and can be liquefied easily in ambient temperature and pressure. Chemical Looping Ammonia Generation (CLAG) is known to be a novel, efficient and environmentally friendly synthesis method for ammonia, in which the N-sorption/desorption of nitrogen carrier are included. The N-sorption step, which is known as the carbothermal reduction, is well studied while there are few reports on N-desorption step. Therefore, in this paper, stationary bed reactor and thermo-gravimetric analyzer (TGA) were used to study the N-desorption performance of the TiO 2 -loaded Al-based N-carrier and the corresponding NH 3 generation during the N-desorption reaction. The results showed that, TiO 2 performed a good catalytic effect on the N-desorption reaction, which is due to the good dissociative adsorption performance of H 2 O on TiO 2 surface, and the released hydroxyl (OH ) plays an important role in the N-desorption reaction. The conversion amount of aluminum nitride and the yield of NH 3 increased with the TiO 2 loading in the reactants, the reaction temperatures and the steam concentrations in the atmosphere, while the conversion efficiency of NH 3 , which is significantly affected by temperature, didn't affected by the TiO 2 loadings. [ABSTRACT FROM AUTHOR]

Doping with foreign atoms is an efficient way to enhance the electrochromic performance of the pristine single material. In this work, N-doped TiO 2 -B nanotube films were successfully prepared via hydrothermal approach combined with ion exchange method. The nitrogen doped TiO 2 -B nanotube film shows good electrochromic performance and cyclic stability. At 633 nm and −1.6 V, the optical modulation amplitude of the nitrogen doped TiO 2 -B film can reach 76%, which is higher than pristine TiO 2 -B film (64%). The coloring efficiency of the nitrogen doped samples is 35.38 cm2/C which is higher than pure TiO 2 -B (21.72 cm2/C). Such good performance can be ascribed to the increase of the TiO 2 -B electrical conductivity caused by the doping of N species. [ABSTRACT FROM AUTHOR]