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Electrochemical reduction of CO2 and H2O to synthesize gas (H2 and CO mixture) is of significant interest due to established industrial pathways to tune the H2 to CO composition to generate an array of valuable products including methanol, synthetic fuel, synthetic natural gas, and hydrogen. However, controlled H2:CO ratios are challenging on CO-active electrocatalysts like silver. We demonstrate that applying laser engineering to adjust the surface wetting state of a silver electrocatalyst with water contact angles θw ranging from 47° and 135°, H2:CO ratios can be tuned from 1 to 4 at modest potentials (−0.7 V versus RHE, RHE—reversible hydrogen electrode) with almost total unity Faradaic efficiency. Both hydrophilic (θw = 47°) and more hydrophobic (θw = 135°) samples showed an increasing H2:CO trend with rising potentials (0.7–1.2 V versus RHE) due to mass transport. Conversely, silver electrocatalyst with θw = 110° exhibited a constant H2:CO ratio of 4. This indicates catalyst wettability potentially affects *H and *HOCO intermediates' adsorption, impacting H2:CO ratios. Our results show the feasibility of syngas composition control on silver catalysts via surface wettability, providing a simpler alternative to complex multicomponent electrocatalytic systems. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effects of laser shock peening (LSP) on the corrosion resistance of lightweight metal alloys, specifically AA6061 and AZ31. LSP was performed underwater, using a nanosecond pulse laser and without using a protective coating or layer on the workpiece. The corrosion behaviors of these alloys were analyzed through electrochemical tests, including open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization measurements. The results demonstrated that LSP significantly improved the polarization resistance, and higher laser power intensities led to increased corrosion resistance and reduced corrosion rates. This enhancement in anti-corrosion performance is attributed to the formation of a protective oxide layer on the surface, acting as a barrier against corrosion. The findings underscore the potential of laser surface treatment as a viable technique for enhancing the corrosion resistance of lightweight metal alloys. [ABSTRACT FROM AUTHOR]

Tin-based chalcogenide semiconductors, though attractive materials for photovoltaics, have to date exhibited poor performance and stability for photoelectrochemical applications. Here, a novel strategy is reported to improve performance and stability of tin monosulfide (SnS) nanoplatelet thin films for H2 production in acidic media without any use of sacrificial reagent. P-type SnS nanoplatelet films are coated with the n-CdS buffer layer and the TiO2 passivation layer to form type II heterojunction photocathodes. These photocathodes with subsequent deposition of Pt nanoparticles generate a photovoltage of 300 mV and a photocurrent density of 2.4 mA cm-2 at 0 V versus reversible hydrogen electrode (RHE) for water splitting under simulated visible-light illumination (λ > 500 nm, Pin = 80 mW cm-2). The incident photon-to-current efficiency at 0 V versus RHE for H2 production reach a maximum of 12.7% at 575 nm with internal quantum efficiency of 13.8%. The faradaic efficiency for hydrogen evolution remains close to unity after 6000 s of illumination, confirming the robustness of the heterojunction for solar H2 production.

Plasmonic metal/semiconductor heterostructures show promise for visible-light-driven photocatalysis. Gold nanorods (AuNRs) semi-coated with TiO2 are expected to be ideally structured systems for hydrogen evolution. Synthesizing such structures by wet-chemistry methods, however, has proved challenging. Here we report the bottom-up synthesis of AuNR/TiO2 nanodumbbells (NDs) with spatially separated Au/TiO2 regions, whose structures are governed by the NRs' diameter, and the higher curvature and lower density of CnTAB surfactant at the NRs' tips than on their lateral surfaces, as well as the morphology's dependence on concentration, and alkyl chain length of CnTAB. The NDs show plasmon-enhanced H2 evolution under visible and near-infrared light.

The optical resonances of plasmonic nanostructures depend critically on the geometrical details of the absorber. We show that this unique property of plasmons can potentially be used to create panchromatic absorbers covering most of the useful solar spectrum, by measuring the light-to-hydrogen conversion capabilities of a series multielectrode photocatalytic devices, based on functionalized gold nanorods of appropriately chosen aspect ratios. Judiciously combining nanorods of various aspect ratios almost doubles the H2 production of the device over what is optimally possible with a device using gold nanorods of a single aspect ratio (all other key parameters being equal). The estimated quantum efficiency (absorbed photons-to-hydrogen) averaged over the entire solar spectrum of the best performing plasmonic multielectrode array was approximately 0.1%, and the measured H2 production rate for all of the devices was found to be approximately proportional to the hot electron generation. The device was monitored continuously for over 200 hr of operation without measurable diminution in the rate.

The conversion of sunlight into electricity by photovoltaics is currently a mature science and the foundation of a lucrative industry. In conventional excitonic solar cells, electron-hole pairs are generated by light absorption in a semiconductor and separated by the "built in" potential resulting from charge transfer accompanying Fermi-level equalization either at a p-n or a Schottky junction, followed by carrier collection at appropriate electrodes. Here we report a stable, wholly plasmonic photovoltaic device in which photon absorption and carrier generation take place exclusively in the plasmonic metal. The field established at a metal-semiconductor Schottky junction separates charges. The negative carriers are high-energy (hot) electrons produced immediately following the plasmon's dephasing. Some of the carriers are energetic enough to clear the Schottky barrier or quantum mechanically tunnel through it, thereby producing the output photocurrent. Short circuit photocurrent densities in the range 70-120 μA cm(-2) were obtained for simulated one-sun AM1.5 illumination with devices based on arrays of parallel gold nanorods, conformally coated with 10 nm TiO2 films and fashioned with a Ti metal collector. For the device with short circuit currents of 120 μA cm(-2), the internal quantum efficiency is ∼2.75%, and its wavelength response tracks the absorption spectrum of the transverse plasmon of the gold nanorods indicating that the absorbed photon-to-electron conversion process resulted exclusively in the Au, with the TiO2 playing a negligible role in charge carrier production. Devices fabricated with 50 nm TiO2 layers had open-circuit voltages as high as 210 mV, short circuit current densities of 26 μA cm(-2), and a fill factor of 0.3. For these devices, the TiO2 contributed a very small but measurable fraction of the charge carriers.

Efficient and cost-effective conversion of solar energy to useful chemicals and fuels could lead to a significant reduction in fossil hydrocarbon use. Artificial systems that use solar energy to produce chemicals have been reported for more than a century. However the most efficient devices demonstrated, based on traditionally fabricated compound semiconductors, have extremely short working lifetimes due to photocorrosion by the electrolyte. Here we report a stable, scalable design and molecular level fabrication strategy to create photoelectrochemically active heterostructure (PAH) units consisting of an efficient semiconductor light absorber in contact with oxidation and reduction electrocatalysts and otherwise protected by alumina. The functional heterostructures are fabricated by layer-by-layer, template-directed, electrochemical synthesis in porous anodic aluminum oxide membranes to produce high density arrays of electronically autonomous, nanostructured, corrosion resistant, photoactive units (~10(9)-10(10) PAHs per cm(2)). Each PAH unit is isolated from its neighbor by the transparent electrically insulating oxide cellular enclosure that makes the overall assembly fault tolerant. When illuminated with visible light, the free floating devices have been demonstrated to produce hydrogen at a stable rate for over 24 h in corrosive hydroiodic acid electrolyte with light as the only input. The quantum efficiency (averaged over the solar spectrum) for absorbed photons-to-hydrogen conversion was 7.4% and solar-to-hydrogen energy efficiency of incident light was 0.9%. The fabrication approach is scalable for commercial manufacturing and readily adaptable to a variety of earth abundant semiconductors which might otherwise be unstable as photoelectrocatalysts.

Nanostructured Schottky inorganic-organic solar cells provide overall power conversion efficiencies exceeding 3%, with extremely large short-circuit photocurrents. The device EQE faithfully tracks the absorptance of the CdSe nanorods, and the IQE is approximately constant over the entire visible spectrum as opposed to a p-n junction hybrid solar cell fabricated with a highly absorbing organic polymer.

Nosocomial infections may result from intensive care unit pulse oximeters. The descriptive study examined pulse oximeter sensor microbiological contamination and the efficacy of manual disinfection with alcohol and sodium hypochlorite in five hospital intensive care units. Sixty-eight reusable pulse oximeter sensors were swabbed, cultured, and evaluated after decontamination. In private and public hospitals, 12 (35.2%) and 13 (37.2%) pulse oximeters tested positive for bacteria. Alcohol 70% reduced the microbial load and more than 10% sodium hypochlorite. The study found that purposeful cleaning and disinfection reduce microorganisms. Alcohol was more efficacious than sodium hypochlorite. Critical care facilities should regularly clean reusable pulse oximeter sensors. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate that highly sensitive conductometric gas nanosensors for [H.sub.2]S can be synthesized by electrodepositing gold nanoparticles on single-walled carbon nanotube (SWNT) networks. Adjusting the electrodeposition conditions allowed for tuning of the size and number of gold nanoparticles deposited. The best [H.sub.2]S sensing performance was obtained with discrete gold nanodeposits rather than continuous nanowires. The gas nanosensors could sense [H.sub.2]S in air at room temperature with a 3 ppb limit of detection. The sensors were reversible, and increasing the bias voltage reduced the sensor recovery time, probably by local Joule heating. The sensing mechanism is believed to be based on the modulation of the conduction path across the nanotubes emanating from the modulation of electron exchange between the gold and carbon nanotube defect sites when exposed to [H.sub.2]S. 10.1021/acg901871d

Objectives: To find out the impact of occupational and socio-demographic factors on the health related quality of life of sewerage and sanitary workers in Karachi. Methods: A cross-sectional study was conducted during 2019. Four hundred workers were chosen from five districts of Karachi using a non-probability convenient sampling technique. An Urdu version of WHO BRIEF quality of life questionnaire was used to collect the data about workers general health status and quality of life. Descriptive analysis was done and Chi-square test was used for the association of socio-demographic factors and quality of life. Multiple regression model was used to predict QOL of all domains. P-value<0.05 was considered as statistically significant. Results: Out of 400 sanitary workers, 228 (57.0%) were sweepers and the rest 172 (43.0) were sewerage workers. The majority of the workers 321 (80.3%) were male and 246 (61.5%) were illiterate. The vast majority of the workers 386 (96.5%) were not immunized against typhoid, / hepatitis and tetanus. Ninetyone percent (91%) were not using any kind of safety gadgets while at work. Male workers, married workers of both sexes and those with some education had a little better quality of life than their counterparts. Sanitary employees likewise had a higher quality of life score than sewage workers (P-value<0.05). Conclusion: The majority of workers, particularly sewage workers, have a very poor quality of life. Along with very bad working circumstances, their standard of living is significantly below par. They were not given any safety equipment. They were handling untreated sewage/waste with their bare hands, and they have never received a typhoid/hepatitis /tetanus vaccine. [ABSTRACT FROM AUTHOR]

Discovery of high-efficiency water-splitting catalysts is critical for clean hydrogen fuel generation. Quantitative and reliable chemical imaging methods can play a crucial role in providing critical catalyst efficiency information for materials development and screening. Here, we developed a reflection optical imaging method to map the performance of transition metal oxide catalysts for oxygen evolution reaction (OER). The generated high concentration of oxygen in the electrolyte will decrease the refractive index of the solutions near the electrode and change the reflectivity of optical images. We successfully imaged and measured the OER on cobalt oxide, and the localized current density and overpotential distribution maps have been extracted. The oxidation and reduction of cobalt oxide can be imaged with our reflection optical imaging method as well. These maps showed that the catalytic activities are quite different at different locations, and some regions showed much higher activities. This is due to the nonuniformity created by the catalyst synthesis process and demonstrates the importance of using the optical imaging method to map the localized catalytic efficiency. In addition, the NiFe alloy's OER catalytic activities have been studied as well. The proposed reflection optical imaging method could find many applications in catalyst activity measurement and screening. [ABSTRACT FROM AUTHOR]

Objective: To assess the health of farmers exposed to pesticides and identify factors associated with the use of personal protective equipment. Methods: This cross-sectional survey was carried out using convenience sampling among 302 farmers in two districts of Punjab in 2021 through an interview-administered questionnaire. The questionnaire covered demographics, information on pesticide exposure, knowledge of PPE use, and self-reported health symptoms. All male pesticide sprayers, regardless of age or socioeconomic condition were included. Asthmatic farmers and non-pesticide applicators were excluded. Spraying by minors under the legal age for employment was also excluded from the study. Data was analysed using SPSS version 23. Frequency tabulation and association between variables were seen using the Chi-square test. P<0.05 is considered as statistically significant. All ethical issues were taken into consideration. Results: The mean age of the respondents was 29.85±10.68 years. Most farmers,168 (55.6%), sprayed pesticides for at least an hour every evening. Liquid pesticides were commonly used by 290 (96.0%) in quantities of up to 20 litres and applied by hand by 265 (88%). The most frequent symptoms were irritation of the eye, nose, and throat, reported by 202 (67%). The farmers used coveralls, 216 (71.5%); face masks, 176 (58.4%); eye goggles, 53 (17.4%); face shields, 26 (8.7%); and aprons, 9 (3.1%). Age, duration, amount of pesticide sprayed, and application method predicted health risks (p<0.05). Conclusion: The study revealed a notable lack of awareness among farmers regarding pesticide spray frequency, quantity, and PPE use. The findings provide valuable insights for policymakers, healthcare professionals and agricultural workers to provide professional training for enhancing the knowledge and practices of farmer's safety and health of pesticide exposure. [ABSTRACT FROM AUTHOR]