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Polymeric carbon nitride modified with selected heteroatom dopants was prepared and used as a model photocatalyst to identify and understand the key mechanisms required for efficient photoproduction of H2O2 via selective oxygen reduction reaction (ORR). The photochemical production of H2O2 was achieved at a millimolar level per hour under visible‐light irradiation along with 100 % apparent quantum yield (in 360–450 nm region) and 96 % selectivity in an electrochemical system (0.1 V vs. RHE). Spectroscopic analysis in spatiotemporal resolution and theoretical calculations revealed that the synergistic association of alkali and sulfur dopants in the polymeric matrix promoted the interlayer charge separation and polarization of trapped electrons for preferable oxygen capture and reduction in ORR kinetics. This work highlights the key features that are responsible for controlling the photocatalytic activity and selectivity toward the two‐electron ORR, which should be the basis of further development of solar H2O2 production.

Iron‐based catalysts have been widely studied for the oxidation of H2S into elemental S. However, the prevention of iron sites from deactivation remains a big challenge. Herein, a facile copolymerization strategy is proposed for the construction of isolated Fe sites confined in polymeric carbon nitride (CN) (Fe‐CNNχ). The as‐prepared Fe‐CNNχ catalysts possess unique 2D structure as well as electronic property, resulting in enlarged exposure of active sites and enhancement of redox performance. Combining systematic characterizations with density functional theory calculation, it is disclosed that the isolated Fe atoms prefer to occupy four‐coordinate doping configurations (Fe–N4). Such Fe–N4 centers favor the adsorption and activation of O2 and H2S. As a consequence, Fe‐CNNχ exhibit excellent catalytic activity for the catalytic oxidation of H2S to S. More importantly, the Fe‐CNNχ catalysts are resistant to water and sulfur poisoning, exhibiting outstanding catalytic stability (over 270 h of continuous operation), better than most of the reported catalysts.

In-depth understanding of microscopic reaction mechanism on nonmetal-doped catalytic system at the atomic level is one of the critical approaches to develop new efficient catalysts. Herein, the effects of S...

A highly efficient Ruddlesden‐Popper structure anode material with a formula of Sr3Fe1.3Mo0.5Ni0.2O7‐δ (RP‐SFMN) has been developed for hydrocarbon fueled solid oxide fuel cells (HF‐SOFC) application. It is demonstrated that a nanostructured RP‐SFMN anode decorated with in‐situ exsolved Ni nanoparticles (Ni@RP‐SFMN) has been successfully prepared by annealing the anode in reducing atmosphere similar to the operating conditions. The phase compositions, valence states, morphologies, and electrocatalytic activities of RP‐SFMN material have been characterized in detail. In addition, the in‐situ exsolution mechanism of the metallic Ni phase from the parent oxide is clearly explained by using density function theory calculation. The peak output power density at 800°C is significantly enhanced from 0.163 to 0.409 W/cm2 while the electrode polarization resistance is effectively lowered from 0.96 to 0.30 Ω cm2 by the substitution of B‐site Fe by Ni, which is attributed to the improved electrocatalytic activities induced by the in‐situ exsolved Ni nanocatalysts. Moreover, the single cell with RP‐SFMN anode exhibits good stability in 3% H2O humidified H2 and syngas for 110 and 60 h at 800°C, respectively. Our findings indicate that RP‐SFMN is a greatly promising anode candidate of HF‐SOFCs due to its good electrochemical performance and stability during the operation.

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Efficient catalytic elimination of hydrogen sulfide (H2S) with high activity and durability in nature gas and blast‐furnace gas is very critical for both fundamental catalytic research and applied environmental chemistry. Herein, atomically dispersed Co atom catalysts with Co–N4 sites that can transform H2S into S with conversion rate of ≈100% are designed and prepared. The representative 4Co‐N/NC achieves a sulfur yield of nearly 100% and TOF(Co) of 869 h–1 at 180 °C. Importantly, remarkable long‐term durability is achieved as well, with no obvious loss of catalytic activity in the run of 460 h, outperforming most of the reported catalysts. The short bond length and strong cooperation of Co–N are beneficial to improve the structural stability of the Co–N4 centers, and significantly enhanced resistance of water and sulfation over single‐atom Co‐catalyst. The present mechanism involves the stepwise hydrogen transfer process via the adsorbed *HOO and *HS intermediates.

Se-modified carbon nitride nanosheets with fluorescent properties and high biocompatibility show efficient free radical cleaning activity, and can be used as biomimetic catalases for resisting oxidative stress.