Hollow fiber carbon membrane for CO2/CH4 separation was successfully synthesized using poly (2,6-dimethyl-1,4-phenylene oxide) (PPO). Pyrolysis parameters, namely pyrolysis temperature, heating rate, and thermal soak time, were optimized based on CO2 permeability and CO2/CH4 ideal selectivity by using Robeson’s 2008 CO2/CH4 upper bound as reference. The optimum CO2 permeability and CO2/CH4 ideal selectivity were 1205.8 Barrer and 194.8, respectively. The surface morphology of PPO and carbon membranes was dense, homogeneous, and symmetrical, with thickness of approximately 15.4 and 14.7 µm, respectively. The crystallinity of the carbon membrane pyrolyzed at the optimum pyrolysis temperature of 600 °C was highly amorphous. The transport mechanism of CO2 through the optimal carbon membrane was dominated by molecular sieving besides surface diffusion. High pyrolysis temperatures reduced the CO2 permeability and increased the CO2/CH4 ideal selectivity. Increasing the heating rate increased the CO2 and CH4 permeabilities and decreased the CO2/CH4 ideal selectivity. Increasing the thermal soaking time increased CO2 permeability without affecting CH4 permeability, thereby increasing the CO2/CH4 ideal selectivity. The CO2 permeability and CO2/CH4 permselectivity from binary test were similar to the CO2 permeability and CO2/CH4 permselectivity from single gas test because of CO2 surface diffusion through the carbon membrane.

We report that transparent mesostructured silica/gold nanocomposite materials with an interpore distance of 4.1 nm, as-synthesized from a templated sol-gel synthesis method using discotic trinuclear gold(I) pyrazolate complex, were successfully utilized for the fabrication of thin film mesoporous silica nanocomposites containing gold nanoparticles. The material exhibited a highly ordered hexagonal structure when subjected to a thermal hydrogen reduction treatment at 210 °C. In contrast, when the material was subjected to calcination as a heat treatment from 190 to 450 °C, the thin film nanocomposites showed an intense d100 X-ray diffraction peak. Moreover, gold nanoparticles inside the thin film nanocomposites were confirmed by the presence of the d111 diffraction peak at 2θ = 38.2°, a surface plasmon resonance peak between 500-580 nm, and the spherical shape observed in the transmission electron microscope images, as well as the visual change in color from pink to purple. Interestingly, by simply dipping the material into a reaction solution of 4-nitrophenol at room temperature, the highly ordered structure of the as-fabricated silica/gold nanoparticle thin film composite after thermal hydrogen reduction at 210 °C resulted in an improved catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol compared to the material calcined at 250 °C. Such catalytic activity is due to the presence of gold nanoparticles of smaller size in the silicate channels of the highly ordered mesoporous film nanocomposites.

The photochemical synthesis of two-dimensional (2D) nanostructured from semiconductor materials is unique and challenging. We report, for the first time, the photochemical synthesis of 2D tin di/sulfide (PS-SnS2-x, x = 0 or 1) from thioacetamide (TAA) and tin (IV) chloride in an aqueous system. The synthesized PS-SnS2-x were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), a particle size distribution analyzer, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), thermal analysis, UV�Vis diffuse reflectance spectroscopy (DR UV�Vis), and photoluminescence (PL) spectroscopy. In this study, the PS-SnS2-x showed hexagonally closed-packed crystals having nanosheets morphology with the average size of 870 nm. Furthermore, the nanosheets PS-SnS2-x demonstrated reusable photo-degradation of methylene blue (MB) dye as a water pollutant, owing to the stable electronic conducting properties with estimated bandgap (Eg) at ~2.5 eV. Importantly, the study provides a green protocol by using photochemical synthesis to produce 2D nanosheets of semiconductor materials showing photo-degradation activity under sunlight response. � 2019 by the authors. Licensee MDPI, Basel, Switzerland.