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Environmental and materials scientists are becoming more interested in catalytic materials for use in filtration and remediation of contaminated gas.. In this study, Ag/SnO2 catalysts were adorned onto a polypropylene (PP) membrane to eliminate nitrogen oxide (NOx) gas. The catalyst-coated membrane achieved an efficiency of 63.62% and exhibited a low generation of nitrogen dioxide (NO2), just 2.51%. It is noteworthy that even after five cycle experiments, the Ag/SnO2/PP catalytic membrane showed remarkable resilience, retaining a high removal efficiency of approximately 58.2%. Furthermore, the catalytic membrane demonstrated a positive trend in transforming NOx into eco-friendly products, hence decreasing the generation of NO2 byproducts. These encouraging findings demonstrate the Ag/SnO2 catalysts' potential for treating contaminated gasses in the near future in catalytic membrane technologies. [ABSTRACT FROM AUTHOR]

The TiO2 nanomaterial is a traditional photocatalyst that was applied externally in environmental and energy fields. However, a large band gap of TiO2 is a limitation of this material in applications in visible-light regions. Sulfur (S) doped TiO2 nanotubes were synthesized with different weight ratios of the S precursor and TiO2 nanotubes by a thermal diffusion process. Techniques including Fourier transform infrared (FTIR), UV-vis diffuse reflection spectroscopy (DRS), photoluminescence spectroscopy (PL), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) were used to confirm the successful doping of the S-TiO2 nanotubes. The treatment of nitrogen oxide (NOx) gas through photocatalysis using S-doped TiO2 nanotubes represents an innovative and environmentally friendly approach. Sulfur doping narrows the band gap of TiO2 nanotubes (from 3.22 to 3.14 eV), allowing for better absorption of visible light. Furthermore, the photocatalytic NOx removal performance of S-TiO2 nanotubes was significantly enhanced with more than 40% NO at 500 ppb, and the efficiency of NO emission decreased significantly after five cycling tests. [ABSTRACT FROM AUTHOR]

Studies about emissions reduction and treatment, and renewable energy generation are sustainable development goals of the United Nations. Therein, photocatalysts have emerged as highly attractive multifunctional materials due to their versatile applications in environmental remediation and energy production. In this study, a bifunctional photocatalyst, TiO2/g-C3N4, was synthesized for the purpose of NOx removal and water splitting. Various weight ratios of commercially available TiO2 were combined with g-C3N4 synthesized through a pyrolysis method. The findings demonstrate that the 10%-TiO2/g-C3N4 composite exhibited a notably high NO removal rate of 48.34% and minimal NO2 yield compared to pure g-C3N4. The incorporation of TiO2 onto g-C3N4 induced bandgap restructuring, resulting in a significant enhancement in photocurrent density, with a maximum increase of 25 μA cm−2 at 1.23 V. Moreover, the combination of g-C3N4 with 10% TiO2 exhibited promising electrocatalytic potential for the oxygen evolution reaction, as indicated by an overpotential of 0.44 V. Overall, the utilization of bifunctional photocatalysis with TiO2/g-C3N4 holds great promise as an effective approach for both NOx removal and water splitting applications. This combination offers potential solutions for addressing environmental challenges and advancing renewable energy technologies. [ABSTRACT FROM AUTHOR]

Traditional TiO2 semiconductor is a promising photocatalyst. However, the extended application of this material for nitrogen oxide (NO) removal under sunlight conditions is becoming an emerging topic in materials science. Combining and modifying TiO2 with carbon materials such as carbon nanotube (CNT) towards applying a promising photocatalyst for gas pollution treatment have received much more significant attention. Herein, we combine and optimize CNT and commercial TiO2 by a ball-milling method towards a better photocatalyst in solar light driven. The analysis results indicated the existence of spherical TiO2 particles with an average diameter of 80–100 nm and CNT with a length and diameter of several nanometers and approximately 8–10 nm in the composites. The photocatalytic NO evaluation under a natural environment simulation model indicates that 0.7%wt CNT in CNT/TiO2 composite (0.7CT sample) achieves the most excellent photocatalysis. The CNT/TiO2 composites also express high stability. However, the CNT/TiO2 composite still has a limitation with a high NO to NO2 conversion yield. [ABSTRACT FROM AUTHOR]

Objective: To investigate the changes of very short-term heart rate variability in HCWs after three hours of wearing PPE to treat COVID-19 patients at different working times and intensities, and related factors. Methods: Sixty-five healthy HCWs were enrolled at the Number 2 Infectious Field Hospital (formed by Military Hospital 103), Vietnam. Two-minute 12-lead electrocardiograms were recorded before wearing and after removing PPE. Results: After three hours of wearing PPE, the mean heart rate of HCWs increased (p = 0.048) meanwhile, the oxygen saturation decreased significantly (p = 0.035). Standard deviation of all normal to normal intervals (SDNN), mean intervals RR (mean NN), and root mean square successive difference (rMSSD) after wearing PPE was also reduced significantly. SDNN, Mean NN, and rMSSD decreased as the working intensity increased (as in mild, moderate, and severe patient departments). In univariate regression analysis, logSDNN, logmean NN and logrMSSD were positively correlated with SpO2 and QT interval (r = 0.14, r = 0.31, r = 0.25; r = 0.39, r = 0.77, r = 0.73, respectively) and were negatively correlated with ambient temperature inside PPE (r = − 0.41, r = − 0.405, r = − 0.25, respectively) while logmean NN and log rMSSD were negatively correlated with diastolic blood pressure (r = − 0.43, r = − 0.39, respectively). In multivariable regression analysis, logSDNN and logmean NN were negatively correlated to ambient temperature inside PPE (r = − 0.34, r = − 0.18, respectively). Conclusion: Time-domain heart rate variability decreased after wearing PPE. Time-domain HRV parameters were related to ambient temperature inside PPE, diastolic blood pressure, QT interval, and SpO2. [ABSTRACT FROM AUTHOR]

In this study, we used Fe2O3/diatomite material system toward ciprofloxacin (CIP) photo-Fenton removal in water under visible light (vis) excitation. The characterization of Fe2O3/diatomite catalysts was determined by X-ray diffraction patterns, Fourier-transform infrared analysis, inductively coupled plasma mass spectrometry, and scanning electron microscopy. The photo-Fenton catalytic activity of the Fe2O3/diatomite was appraised by the removal efficiency of the CIP throughout the effect of the H2O2 with various parameters such as initial pH, catalyst amount, and H2O2 amount. The results indicate that 0.2 gL−1 Fe2O3/diatomite catalysts achieved the highest performance at approximately 90.03% with a 50 μL H2O2 concentration. Furthermore, the Fe2O3/diatomite catalysts have high stability, with over 80% CIP removed after five cycles. This study is inspired to develop a potential material for photo-Fenton degradation of antibiotics in wastewater. [ABSTRACT FROM AUTHOR]

To date, hybrid polyvinyl alcohol (PVA) and TiO2 nanocomposites have been widely studied for numerous practical applications including enhanced visible-light photocatalytic activities, shield coatings against UV light, electrolyte membranes for fuel cells, hybrid fibers and proton conduction layers in biological systems. However, the properties of interaction between PVA and the TiO2 surface, particularly the band offset of organic–inorganic constituents, are still unclear and under debate. In this work, we studied the resistive switching characteristics and mechanism of hybrid PVA and TiO2 nanotube (TNT) nanocomposites. By embedding TNTs into the PVA matrix, the resistive switching performance of devices is significantly enhanced, with an excellent retention of 104 seconds and large resistance ratio ＞104. Density functional theory (DFT) calculations confirmed that strong bonds were formed between the O atoms in PVA's OH groups and the five-coordinated Ti atoms on the surface of TiO2, corresponding to the significant decrease of vibrational intensity of the OH-group in the FTIR spectra. In addition, band offsets of the TiO2/PVA interface illustrated the very low minimum conduction band energy level of TiO2 compared to that of crystalline PVA, implying that TNTs act as trap centers for electrons in the insulating layer. Consequently, the current transport and switching mechanisms of the devices were suggested using the models of trap controlled space-charge-limited conduction and the charge carrier trapping–de-trapping process at the centers of TNTs in the PVA polymer matrix, respectively. [ABSTRACT FROM AUTHOR]

TiO 2 nanotube arrays (TNAs) have been studied for photoelectrochemical (PEC) water splitting. However, there are two major barriers of TNAs, including a low photo-response and the fast charge carrier recombination in TNAs, leading to poor photocatalytic efficiency. Through a comparison of MoS 2 /TNAs and g-C 3 N 4 /TNAs, it was found that TNAs modified with MoS 2 and g-C 3 N 4 exhibited a current density of, respectively, 210.6 and 139.6 μA·cm -2 at an overpotential of 1.23 V vs RHE, which is 18.2 and 12 times higher than that of pure TNAs under the same conditions. The stability of the MoS 2 /TNAs heterojunction is higher than that of g-C 3 N 4 /TNAs., (Copyright © 2022, Nguyen et al.)

Nitric oxide (NO) removal by photocatalytic oxidation over g-C 3 N 4 has achieved more efficient results. However, there is a concern about the high NO-to-NO 2 conversion yield of products, which is not suitable for the photocatalytic NO reaction. In this study, we modify g-C 3 N 4 by WO 3 nanoplates for the first time for photocatalytic NO oxidation over a WO 3 /g-C 3 N 4 composite to enhance the green product selectivity under atmospheric conditions. The results indicate that the photocatalytic efficiency for NO removal by the WO 3 /g-C 3 N 4 composite is drastically improved and achieves 52.5%, which is approximately 2.1 times higher than that of pure g-C 3 N 4 . Significantly, the green product (NO 3 - ) selectivity of the WO 3 /g-C 3 N 4 composite is 8.7 times higher than that of pure g-C 3 N 4 , and the selectivity remained high even after five cycles of photocatalytic tests. We also conclude that the enhanced green product selectivity of photocatalytic NO oxidation by the WO 3 /g-C 3 N 4 composite is due to the separation and acceleration of the photogenerated charges of the WO 3 /g-C 3 N 4 S-scheme heterojunction.

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., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)