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Photodynamic therapy (PDT) has emerged as a promising approach for tumor treatment. However, traditional type II PDT faces limitations due to its oxygen-dependent nature. Type-I photosensitizers (PSs) exhibit superiority over conventional type-II PSs owing to their diminished oxygen dependence. Nevertheless, designing effective type-I PSs remains a significant challenge. In this work, we provide a novel strategy to tune the PDT mechanism of an excited photosensitizer through aryl substituent engineering. Using S-rhodamine as the base structure, three PSs were synthesized by incorporating phenyl, furyl, or thienyl groups at the meso position. Interestingly, furyl- or thienyl-substituted S-rhodamine are type-I-dominated PSs that produce O2˙−, while phenyl S-rhodamine results in O2˙− and 1O2 through type-I and type-II mechanisms, respectively. Experimental analyses and theoretical calculations showed that the introduction of a five-membered heterocycle at the meso position promoted intersystem crossing (ISC) and electron transfer, facilitating the production of O2˙−. Furthermore, furyl- or thienyl-substituted S-rhodamine exhibited high phototoxicity at ultralow concentrations. Thienyl-substituted S-rhodamine showed promising PDT efficacy against hypoxic solid tumors. This innovative strategy provides an alternative approach to developing new type-I PSs without the necessity for creating entirely new skeletons. [ABSTRACT FROM AUTHOR]

To increase the radioactivity of 99mTc in the eluent to meet the needs of medical diagnosis, finding a new type of high-efficiency molybdenum and technetium separation material is important. In this study, a viologen-based cationic organic polymer (VBCOP) was prepared and its adsorption toward ReO-4 and MoO2-4 was studied. The influence of pH, the initial concentration of Mo and Re was investigated. In addition, the sorption performance of VBCOP on Re in solutions containing different molar ratios between Re (10 mg·L-1) and Mo was studied. The results show that VBCOP has excellent sorption performance for Re and good selectivity. VBCOP can show good adsorption performance in a wide range of pH, and the effect of alkaline conditions on Mo is greater than that on Re. The saturated sorption capacity of VBCOP for ReO-4 reaches 597 mg·g-1 and the saturated sorption capacity for MoO2-4 is 196 mg·g-1. Under neutral conditions, and when the Re∶Mo molar ratio is 1∶10 000, VBCOP can still exhibit a certain adsorption effect on ReO-4 (35%), which is expected to pave the way for further research.

Nitrate (NO3‒) pollution poses significant threats to water quality and global nitrogen cycles. Alkaline electrocatalytic NO3‒ reduction reaction (NO3RR) emerges as an attractive route for enabling NO3‒ removal and sustainable ammonia (NH3) synthesis. However, it suffers from insufficient proton (H+) supply in high pH conditions, restricting NO3‒-to-NH3 activity. Herein, we propose a halogen-mediated H+ feeding strategy to enhance the alkaline NO3RR performance. Our platform achieves near-100% NH3 Faradaic efficiency (pH = 14) with a current density of 2 A cm–2 and enables an over 99% NO3–-to-NH3 conversion efficiency. We also convert NO3‒ to high-purity NH4Cl with near-unity efficiency, suggesting a practical approach to valorizing pollutants into valuable ammonia products. Theoretical simulations and in situ experiments reveal that Cl-coordination endows a shifted d-band center of Pd atoms to construct local H+-abundant environments, through arousing dangling O-H water dissociation and fast *H desorption, for *NO intermediate hydrogenation and finally effective NO3‒-to-NH3 conversion. Alkaline nitrate electroreduction to ammonia is restricted by insufficient H+ supply. Here, the authors propose a halogen-mediated H+ feeding strategy, by triggering dangling O-H water dissociation and fast *H desorption for *NO intermediate hydrogenation, to enhance the formation of ammonia. [ABSTRACT FROM AUTHOR]

Electrochemical CO2 reduction reaction (CO2RR) is crucial to addressing environmental crises and producing chemicals. Proton activation and transfer are essential in CO2RR. To date, few research reviews have focused on this process and its effect on catalytic performance. Recent studies have demonstrated ways to improve CO2RR by regulating proton transfer dynamics. This Concept highlights the use of regulating proton transfer dynamics to enhance CO2RR for the target product and discusses modulation strategies for proton transfer dynamics and operative mechanisms in typical systems, including single‐atom catalysts, molecular catalysts, metal heterointerfaces, and organic‐ligand modified metal catalysts. Characterization methods for proton transfer dynamics during CO2RR are also discussed, providing powerful tools for the hydrogen‐involving electrochemical study. This Concept offers new insights into the CO2RR mechanism and guides the design of efficient CO2RR systems. [ABSTRACT FROM AUTHOR]