The anatase-rutile phase transformation of TiO(2) bulk material is investigated using a density functional theory (DFT) approach in this study. According to the calculations employing the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional with the Vanderbilt ultrasoft pseudopotential, it is suggested that the anatase phase is more energetically stable than rutile, which is in variance with the experimental observations. Consequently, the DFT + U method is employed in order to predict the correct structural stability in titania from electronic-structure-based total energy calculations. The Hubbard U term is determined by examining the band structure of rutile with various values of U from 3 to 10 eV. At U = 5 eV, a theoretical bandgap for rutile is obtained as 3.12 eV, which is in very good agreement with the reported experimental bandgap. Hence, we choose the DFT + U method (with U = 5 eV) to investigate the transformation pathway using the newly-developed solid-state nudged elastic band (ss-NEB) method, and consequently obtain an intermediate transition structure that is 9.794 eV per four-TiO(2) above the anatase phase. When the Ti-O bonds in the transition state are examined using charge density analysis, seven Ti-O bonds (out of 24 bonds in the anatase unit cell) are broken, and this result is in excellent agreement with a previous experimental study (Penn and Banfield 1999 Am. Miner. 84 871-6).

We report on the process of synthesizing copper nanoparticles (Cu Nps) for a short reactive time by chemical reduction method with a support of CTAB reductive agent. Their properties were determined by ultraviolet-visible (UV-Vis) absorption spectrum, the X-ray (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), and Transmission Electron Microscopy (TEM) images. The antifungal activity of Cu Nps was evaluated by testing againstFusariumsp. The Cu Nps were obtained with the average size in the range of 20–50 nm having spherical shape. The survey shows that when Cu Nps were used at 450 ppm concentration in 9-day incubation, 93.98% of fungal growth was inhibited.

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The residue of antibiotics in the water has led to increased antibioticresistant bacteria, harm to human health, and damage to health-beneficial healthy bacteria. An idea of constructing S-scheme α-Fe 2 O 3 /g-C 3 N 4 nanocomposites is studied toward a photocatalysis application for an efficient resolution of commercial antibiotics in wastewater. Outstanding S-scheme Fe 2 O 3 /g-C 3 N 4 nanocatalysts are synthesized by a straightforward method and could easily improve the recycling property, thanks to magnetic materials. Empirical results indicate that S-scheme Fe 2 O 3 /g-C 3 N 4 photocatalysts can degrade commercial cefalexin and amoxicillin (20 mg L −1 ) under visible light, with five and nine times higher performance than that of g-C 3 N 4 , respectively. Furthermore, the detailed evidence to propose S-scheme Fe 2 O 3 /g-C 3 N 4 heterojunctions and comparison of photocatalytic performance in antibiotic degradation have also been mentioned in this study. KEYWORDS: α-Fe 2 O 3 , g-C 3 N 4 , photocatalysis, α-Fe 2 O 3 /g-C 3 N 4 , S-scheme, antibiotic degradation

In this paper, Pt nanoparticles were successfully prepared by modified polyol method using silver nitrate as an effective structure-modifying agent. The characterization of Pt nanoparticles was investigated by using UV-Vis-NIR spectroscopy, transmission electron microscopy (TEM) and high resolution (HR) TEM, and x-ray diffraction (XRD). The method of selected area electron diffraction (SEAD) was used to study the structure of Pt nanoparticles. The results showed that the as-prepared Pt nanoparticles exhibiting the complexity of surface structure and morphology could be used as efficient catalysts for polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs).

The pursuit of robust photocatalysts that can completely degrade organic contaminants with high performance as well as high energy efficiency, simplicity in preparation, and low cost is an appealing topic that potentially promotes photocatalysts for being used widely. Herein, we introduce a new and efficient SnO 2 /Bi 2 S 3 /BiOCl–Bi 24 O 31 Cl 10 (SnO 2 /Bi 2 S 3 -Bi25) composite photocatalyst by taking advantage of the robust, simple, and potentially scalable one-pot synthesis, including the hydrothermal process followed by thermal decomposition. Interestingly, we observed the formation of BiOCl–Bi 24 O 31 Cl 10 (abbreviated as Bi25) heterojunctions derived from reactions between Bi 2 S 3 and SnCl 4 ·5H 2 O precursor solutions under the hydrothermal condition and thermal decomposition of BiOCl. This Bi25 heterojunction acts as an interface to reduce the recombination of photogenerated electron–hole (e – –h + ) pairs as well as to massively enhance the visible light harvesting, thereby significantly enhancing the photocatalytic degradation performance of the as-prepared composite photocatalyst. In detail, the photocatalytic degradation of Rhodamine B (RhB) activated by visible light using 15% SnO 2 /Bi 2 S 3 -Bi25 shows the efficiency of 80.8%, which is superior compared to that of pure Bi 2 S 3 (29.4%) and SnO 2 (0.1%). The SnO 2 /Bi 2 S 3 -Bi25 composite photocatalyst also presents an excellent photostability and easy recovery from dye for recycling. The trapping test revealed that the photogenerated holes play a crucial factor during the photocatalytic process, whereas superoxide radicals are also formed but not involved in the photocatalytic process. Successful fabrication of SnO 2 /Bi 2 S 3 -Bi25 composite photocatalysts via a straightforward method with drastically enhanced photocatalytic performance under visible light activation would be useful for practical applications.

This is the first time the SnO2/PANI nanocomposite was utilized for the nitrogen oxide (NO) photocatalytic degradation. In addition, the properties of the SnO2/PANI nanocomposite were deeply studied by various characterizations. The results showed that the photostability of PANI has been improved and the SnO2/PANI nanocomposite demonstrated the efficient NO photocatalytic degradation. Notably, in this work, the adsorption and photocatalytic mechanisms, polymer photodegradation, and the band structure of the SnO2/PANI nanocomposite were fully and systematically investigated via experimental measurements and density functional theory (DFT).

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