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Identification of different mitochondrial reactive oxygen species (ROS) simultaneously in living cells is vital for understanding the critical roles of different ROS in biological processes. To date, it remains a great challenge to develop ROS probes for direct and simultaneous identification of multiple ROS with high specificity. Herein, we report a SERS‐borrowing‐strategy‐based nanoprobe (Au@Pt core–shell nanoparticles) for simultaneous and direct identification of different ROS by their distinct Raman fingerprints. Isotope substitution experiments and DFT calculations confirmed the ability of Au@Pt nanoprobe to capture and identify different mitochondrial ROS (i.e. ⋅OOH, H2O2, and ⋅OH). When functionalized with triphenylphosphine (TPP), the Au@Pt‐TPP nanoprobe located to mitochondria and detected multiple ROS simultaneously in living cells under oxidative stimulation. Our method offers a new tool for the study of the functions of various ROS in biological processes. [ABSTRACT FROM AUTHOR]

Identification of different mitochondrial reactive oxygen species (ROS) simultaneously in living cells is vital for understanding the critical roles of different ROS in biological processes. To date, it remains a great challenge to develop ROS probes for direct and simultaneous identification of multiple ROS with high specificity. Herein, we report a SERS‐borrowing‐strategy‐based nanoprobe (Au@Pt core–shell nanoparticles) for simultaneous and direct identification of different ROS by their distinct Raman fingerprints. Isotope substitution experiments and DFT calculations confirmed the ability of Au@Pt nanoprobe to capture and identify different mitochondrial ROS (i.e. ⋅OOH, H2O2, and ⋅OH). When functionalized with triphenylphosphine (TPP), the Au@Pt‐TPP nanoprobe located to mitochondria and detected multiple ROS simultaneously in living cells under oxidative stimulation. Our method offers a new tool for the study of the functions of various ROS in biological processes. [ABSTRACT FROM AUTHOR]

Precise control and accurate understanding of the ordering degree of bimetallic nanocatalysts (BNs) are challenging yet crucial to acquire advanced materials for the oxygen reduction reaction (ORR). AuCu BNs with various ordering degrees were synthesized to evaluate the influence of ordering degree on the ORR at a molecular level using in situ Raman spectroscopy. The activity of AuCu BNs was improved by over 2 times after a disorder‐to‐order transition, making the performance of highly ordered AuCu BNs exceed that of benchmark Pt/C. Direct Raman spectroscopic evidence of key intermediate (*OH) demonstrates that the active site is the combination site of Au and Cu. Moreover, two distinct *OH species are observed on the ordered and disordered structure, and the ordered site is more beneficial for ORR due to its lower affinity to *OH. This work deepens the understanding on the important role of ordering degree on BNs and enables the design of improved catalysts. [ABSTRACT FROM AUTHOR]

Precise control and accurate understanding of the ordering degree of bimetallic nanocatalysts (BNs) are challenging yet crucial to acquire advanced materials for the oxygen reduction reaction (ORR). AuCu BNs with various ordering degrees were synthesized to evaluate the influence of ordering degree on the ORR at a molecular level using in situ Raman spectroscopy. The activity of AuCu BNs was improved by over 2 times after a disorder‐to‐order transition, making the performance of highly ordered AuCu BNs exceed that of benchmark Pt/C. Direct Raman spectroscopic evidence of key intermediate (*OH) demonstrates that the active site is the combination site of Au and Cu. Moreover, two distinct *OH species are observed on the ordered and disordered structure, and the ordered site is more beneficial for ORR due to its lower affinity to *OH. This work deepens the understanding on the important role of ordering degree on BNs and enables the design of improved catalysts. [ABSTRACT FROM AUTHOR]

Elucidating hydrogen oxidation reaction (HOR) mechanisms in alkaline conditions is vital for understanding and improving the efficiency of anion‐exchange‐membrane fuel cells. However, uncertainty remains around the alkaline HOR mechanism owing to a lack of direct in situ evidence of intermediates. In this study, in situ electrochemical surface‐enhanced Raman spectroscopy (SERS) and DFT were used to study HOR processes on PtNi alloy and Pt surfaces, respectively. Spectroscopic evidence indicates that adsorbed hydroxy species (OHad) were directly involved in HOR processes in alkaline conditions on the PtNi alloy surface. However, OHad species were not observed on the Pt surface during the HOR. We show that Ni doping promoted hydroxy adsorption on the platinum‐alloy catalytic surface, improving the HOR activity. DFT calculations also suggest that the free energy was decreased by hydroxy adsorption. Consequently, tuning OH adsorption by designing bifunctional catalysts is an efficient method for promoting HOR activity. [ABSTRACT FROM AUTHOR]

Elucidating hydrogen oxidation reaction (HOR) mechanisms in alkaline conditions is vital for understanding and improving the efficiency of anion‐exchange‐membrane fuel cells. However, uncertainty remains around the alkaline HOR mechanism owing to a lack of direct in situ evidence of intermediates. In this study, in situ electrochemical surface‐enhanced Raman spectroscopy (SERS) and DFT were used to study HOR processes on PtNi alloy and Pt surfaces, respectively. Spectroscopic evidence indicates that adsorbed hydroxy species (OHad) were directly involved in HOR processes in alkaline conditions on the PtNi alloy surface. However, OHad species were not observed on the Pt surface during the HOR. We show that Ni doping promoted hydroxy adsorption on the platinum‐alloy catalytic surface, improving the HOR activity. DFT calculations also suggest that the free energy was decreased by hydroxy adsorption. Consequently, tuning OH adsorption by designing bifunctional catalysts is an efficient method for promoting HOR activity. [ABSTRACT FROM AUTHOR]

A type of high‐efficiency boiling heat transfer (BHT) interfaces based on superhydrophilic copper microcavity and nanocone (CMN) composite structure are reported. In principle, these microcavities are efficient nucleation sites, facilitating decreasing surface superheat required for onset of nucleation boiling (ONB) and enhancing heat transfer coefficient (HTC); discrete nanotips facilitate the departure of boiling bubbles at smaller scale; shallow microcavities with depth of a few micrometers can avoid excess interface thermal resistance; and the superwetting effect of structure itself helps improve critical heat flux (CHF). Through exploring morphology, wettability, boiling mass and heat transfer properties of CMN structures varied with growth time, an optimal interface is obtained with 142% enhancement in the maximum HTC, 64% enhancement in CHF, and 33% decrease in the ONB superheat as compared to the flat copper surface. Meanwhile, combined experiments and theoretical analyses also clarify why the in situ growth of CMN structures on the copper surface can effectively enhance BHT and why the BHT enhancement effects become worse as the growth time of CMN structure increases. This work not only widens the application scope of superwetting surfaces but offers new insight how to rationally design superhydrophilic micro‐ and nanostructures so as to achieve more efficient BHT. [ABSTRACT FROM AUTHOR]