Boosting selectivity towards formate production using CuAl alloy nanowires by altering the CO2 reduction reaction pathway.

Understanding the fundamentals behind an electrocatalyst's selectivity enables the ability to steer product formation. Herein, we study Cu nanowires doped with a small amount of Al (12%) for CO2R, which enhances formate production by 16.9% over pure Cu nanowires. Density functional theory calculations and COR were employed to posit the preference of the formate formation pathway as a result of the Al doping.

Selective electrochemical reduction of CO2 on compositionally variant bimetallic Cu-Zn electrocatalysts derived from scrap brass alloys.

The electrocatalytic reduction of carbon dioxide (CO2RR) into value-added fuels is a promising initiative to overcome the adverse effects of CO2 on climate change. Most electrocatalysts studied, however, overlook the harmful mining practices used to extract these catalysts in pursuit of achieving high-performance. Repurposing scrap metals to use as alternative electrocatalysts would thus hold high privilege even at the compromise of high performance. In this work, we demonstrated the repurposing of scrap brass alloys with different Zn content for the conversion of CO2 into carbon monoxide and formate. The scrap alloys were activated towards CO2RR via simple annealing in air and made more selective towards CO production through galvanic replacement with Ag. Upon galvanic replacement with Ag, the scrap brass-based electrocatalysts showed enhanced current density for CO production with better selectivity towards the formation of CO. The density functional theory (DFT) calculations were used to elucidate the potential mechanism and selectivity of the scrap brass catalysts towards CO2RR. The d-band center in the different brass samples with different Zn content was elucidated.

Cost-Effective Face Mask Filter Based on Hybrid Composite Nanofibrous Layers with High Filtration Efficiency.

One of the main protective measures against COVID-19's spread is the use of face masks. It is therefore of the utmost importance for face masks to be high functioning in terms of their filtration ability and comfort. Notwithstanding the prevalence of the commercial polypropylene face masks, its effectiveness is under contention, leaving vast room for improvement. During the pandemic, the use of at least one mask per day for each individual results in a massive number of masks that need to be safely disposed of. Fabricating biodegradable filters of high efficiency not only can protect individuals and save the environment but also can be sewed on reusable/washable cloth masks to reduce expenses. Wearing surgical masks for long periods of time, especially in hot regions, causes discomfort by irritating sensitive facial skin and warmed inhaled air. Herein, we demonstrate the fabrication of novel electrospun composites layers as face mask filters for protection against pathogens and tiny particulates. The combinatorial filter layers are made by integrating TiO2 nanotubes as fillers into chitosan/poly(vinyl alcohol) polymeric electrospun nanofibers as the outer layer. The other two filler-free layers, chitosan/poly(vinyl alcohol) and silk/poly(vinyl alcohol) as the middle and inner composite layers, respectively, were used for controlled protection, contamination prevention, and comfort for prolonged usage. The ASTM standards evaluation tests were adopted to evaluate the efficacy of the assembled filter, revealing high filtration efficiency compared to that of commercial surgical masks. The TiO2/Cs/PVA outer layer significantly reduced Staphylococcus aureus bacteria by 44.8% compared to the control, revealing the dual effect of TiO2 and chitosan toward the infectious bacterial colonies. Additionally, molecular dynamics calculations were used to assess the mechanical properties of the filter layers.