Facet-Controlled Cu2O Support Enhances Catalytic Activity of Pt Nanoparticles for CO Oxidation

Advancing polarity-transcendent design: Development of a photoelectrochemical sensor with extended detection range

In photoelectrochemical (PEC) sensors, traditional detection modes such as "signal-on", "signal-off", and "polarity-switchable" limit target signals to a single polarity range, necessitating novel design strategies to enhance the operational scope. To overcome this limitation, we propose, for the first time, a "polarity-transcendent" design concept that enables a continuous response across the polarity spectrum, significantly broadening the sensor's concentration detection range. This concept is exemplified in our new "background-enhanced signal-off polarity-switchable" (BESOPS) mode, where the model analyte let-7a activates a cascade shearing reaction of a DNAzyme walker in conjunction with CRISPR/Cas12a, quantitatively peeling off Cu2O-H2 strands at the Cu2O/TiO2 electrode interface to expose the TiO2 surface. This exposure generates an anodic photocurrent at the expense of the cathodic photocurrent from Cu2O/TiO2, facilitating a seamless transition of the target signal from cathodic to anodic. Through systematic experiments and comparative analyses, the BESOPS sensor demonstrates highly sensitive and precise quantification of let-7a, with a detection limit of 2.5 aM and a broad operating range of 10 aM to 10 nM. Its performance exceeds most reported sensor platforms, highlighting the significant potential of our polarity-transcendent design in expanding the operational range of PEC sensors. This innovative approach paves the way for developing next-generation PEC sensors with enhanced applicability and heightened sensitivity in various critical fields.

Recent advances in noble metal-based catalysts for CO oxidation

Carbon monoxide, one of the major pollutants in the air, is mainly produced due to the incomplete combustion of fossil fuels such as coal and oil. Among all the techniques developed for removing CO, catalytic oxidation has been considered one of the most effective approaches, and the commonly used catalysts include metal oxides and noble metals. Noble metal attracted extensive attention due to its good catalytic performance at low temperatures and high resistance to poisoning. The review summarizes the recent advances of noble metals including Pt, Pd, Au, Ru, Rh, and Ir in CO oxidation. The effect of support, metal doping, the particle size of noble metals, and the hydroxyl groups on CO oxidation is discussed. Besides, the metal-support interaction on the stability and activity is also involved in this review. Finally, the challenges and opportunities of supported noble metal catalysts in practical CO oxidation are proposed.

Tuning the Catalytic Selectivity Toward C2+ Oxygenate Products by Manipulating Cu Oxidation States in CO Electroreduction

Enhancing the reaction selectivity for multicarbon products (C2+) is an important goal for the electrochemical CO(2) reduction (ECO(2)R) process. Cuprous compounds have demonstrated promising C2+ selectivity in the ECO(2)R process, but further investigation is necessary to thoroughly elucidate their catalytic behavior toward C2+ oxygenate production. In this study, copper nitride-based materials with varying reduction rates were employed as precatalysts. Consequently, a relationship between the selectivity toward C2+ oxygenates and the Cu oxidation state during the ECOR process is established. Results of theoretical and experimental analyses reveal that the Cu0/Cu+ interface plays a key role in enhancing *CO adsorption while lowering the formation energy of *CH2CO, thereby promoting acetate production. This work highlights the significance of the Cu0/Cu+ interface in the regulation of C2+ oxygenate production and paves the way for the development of highly selective catalysts in the future.