Porous TiO 2 films decorated with Bi 2 O 3 nanoparticles are fabricated via alkalihydrothermal of titanium (Ti) plate by varying the reaction time. The amorphous TiO 2 is transformed into anatase after annealing the films at 500°C in air. The p-type Bi 2 O 3 nanoparticles are successfully assembled on the surface of porous n-type TiO 2 films through the ultrasonic-assisted successive ionic layer adsorption and reaction (SILAR) technique to form Bi 2 O 3 /TiO 2 nanostructure by the two cycles. The obtained Bi 2 O 3 /TiO 2 films are consisted of a well-ordered and uniform porous structure with an average pore diameter of about 100-200 nm containing homogeneously dispersed Bi 2 O 3 nanoparticles of~5 nm diameter. Moreover, the resultant composites present excellent photocatalytic performance toward methyl blue (MB) degradation under UV and visible light irradiation, which could be mainly ascribed to the enhanced light adsorption capacity of unique composite structure and the formation of p-n heterojunctions in the porous Bi 2 O 3 /TiO 2 films. This research is helpful to design and construct the highly efficient heterogeneous semiconductor photocatalysts.

Vinyl Benzoate/Heptadecafluorodecyl acrylate (VBe/HFDA) co-polymers were synthesized and characterized as thickening agents for supercritical carbon dioxide (SC-CO2). The solubility and thickening capability of the co-polymer samples in SC-CO2 were evaluated by measuring cloud point pressure and relative viscosity. The molecular dynamics (MD) simulation for all atoms was employed to simulate the microscopic molecular behavior and the intermolecular interaction of co-polymer–CO2 systems. We found that the introduction of VBe group decreased the polymer–CO2 interaction and increased the polymer–polymer interaction, leading to a reduction in solubility of the co-polymers in SC-CO2. However, the co-polymer could generate more effective inter-chain interaction and generate more viscosity enhancement compared to the Poly(Heptadecafluorodecyl) (PHFDA) homopolymer due to the driving force provided by π-π stacking of the VBe groups. The optimum molar ratio value for VBe in co-polymers for the viscosity enhancement of SC-CO2 was found to be 0.33 in this work. The P(HFDA0.67-co-VBe0.33) was able to enhance the viscosity of SC-CO2 by 438 times at 5 wt. %. Less VBe content would result in a lack of intermolecular interaction, although excessive VBe content would generate more intramolecular π-π stacking and less intermolecular π-π stacking. Both conditions reduce the thickening capability of the P(HFDA-co-VBe) co-polymer. This work presented the relationship between structure and performance of the co-polymers in SC-CO2 by combining experiment and molecular simulations.

A binary nanocomposite composed of two-dimensional (2D) ultrathin ZnIn 2 S 4 nanosheets and one-dimension (1D) TiO 2 nanobelts was prepared and applied as a noble-metal-free photocatalyst for hydrogen evolution under solar-light irradiation. The TiO 2 nanobelt/ZnIn 2 S 4 nanosheet heterojunction nanocomposites show higher light absorption capacity, larger surface area and higher separation of charge carriers in comparison to pristine TiO 2 and ZnIn 2 S 4 . As a result, the hydrogen production over the TiO 2 /ZnIn 2 S 4 nanocomposite with 15 wt% TiO 2 can reach up to 348.21 μmol•g −1 •h −1 , even without noble metals, which is about 26 and 2.3 times higher than the pristine TiO 2 and ZnIn 2 S 4 , respectively. Meanwhile, a possible photocatalytic mechanism of TiO 2 /ZnIn 2 S 4 heterojunction nanocomposites was proposed and corroborated by photoluminescence (PL) spectroscopy and photoelectrochemical (PEC) results. This work paves a way for developing low-cost and high-efficiency noble-metal-free photocatalytic systems for solar-to-hydrogen evolution.

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