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Chemodynamic therapy (CDT) is a tumor-specific intervention methodology, which is based on the upregulation of reactive oxygen species (ROS) content by triggering the Fenton or Fenton-like reaction within the tumor microenvironment (TME). However, there are still challenges in achieving high-efficiency CDT on account of both the limited intracellular hydrogen peroxide (H2O2) and delivery efficiency of Fenton metal ions. Copper-based nanotherapeutic systems have attracted extensive attention and have been widely applied in the construction of nanotherapeutic systems and multimodal synergistic therapy. Herein, we propose a strategy to synergize chemotherapy drugs that upregulate intracellular ROS content with chemodynamic therapy and construct an artemisinin-copper nanoprodrug for proof-of-concept. With the proposed biomimetic self-assembly strategy, we successfully construct an injectable nanoprodrug with suitable size distribution and high drug loading content (68.1 wt%) through the self-assembly of amphiphilic artemisinin prodrug and copper ions. After reaching the TME, both Cu2+ ions and free AH drugs can be released from AHCu nanoprodrugs. Subsequently, the disassembled Cu2+ ions are converted into Cu+ ions by consuming the intracellular GSH. The generated Cu+ ions serve as a highly efficient Fenton-like reagent for robust ROS generation from both AH and tumor-over-produced H2O2. Results show that the nanoprodrug can realize the cascade amplification of ROS generation via artemisinin delivery and subsequent in situ Fenton-like reaction and a high tumor inhibition rate of 62.48% in vivo. This work provides a promising strategy for the design and development of an efficient nanoprodrug for tumor-specific treatment. [ABSTRACT FROM AUTHOR]

According to the d-band center theory of transition-metals, s-block main group metals with fewer valence electrons and delocalized s/p-orbitals are considered to exhibit poor electrocatalytic activity. Therefore, single-atom catalysts (SACs) for CO2 electroreduction to CO primarily focus on transition metal and p-block main group metal atoms as active centers. Herein, we prepared a porous carbon material doped with N/O coordinated K atoms using a simple high-temperature solid-phase synthesis method. The synthesized K–N, O/C catalyst demonstrates remarkable CO selectivity with Faraday efficiency (FE) exceeding 90% over a wide potential window between −0.5 V and −0.9 V versus the reversible hydrogen electrode (vs. RHE). Moreover, the catalyst exhibits a maximum FE of 97.8% towards CO at −0.6 V vs. RHE. In situ attenuated total reflectance infrared spectroscopy (ATR-FTIR) confirms the formation of *COOH on the K–N, O/C catalysts. Through Density Functional Theory (DFT) calculations, we screen out the most possible coordination structures. The K–O2 and K-pyrrolic-N2 models show significantly high CO2 reduction activity. Heteroatom doping induces partial overlap of the electronic states of the s and p orbitals of the K atom with the p orbitals of the coordinated O atom or N atom, thus modulating the electronic structure of the K atom into the catalytically active center for the conversion of CO2 to CO. [ABSTRACT FROM AUTHOR]

Metallic bismuth (Bi) can maintain a stable structure at high reduction potential during the CO2 reduction reaction (CO2RR) process; however, it is limited by its relatively unfavorable catalytic activity. To address this limitation, an effective strategy of electronic structure modulation can be employed to optimize the adsorption energy of reaction intermediates for enhancing CO2RR performance. Based on this principle, we have developed a highly efficient and stable electrocatalyst comprising metallic Ce-doped Bi(0) nanoparticles encapsulated in a porous carbon framework. This catalyst exhibits a substantial improvement in CO2RR activity compared with its undoped counterpart, driving a current density of 13.7 mA cm−2 with a faradaic efficiency of 97.2% for formate production at −1.1 V versus the reversible hydrogen electrode. Furthermore, long-term stability was achieved with an average faradaic efficiency close to 94% during a 48 hour electrocatalytic test. Density functional theory calculations, combined with the in situ attenuated total reflectance infrared (ATR-IR) spectroscopic study, indicate that the doping of Ce enriches the electron density around Bi, consequently enhancing the binding energy between the Bi active centers and *OCHO intermediates, thereby lowering the energy barrier for the CO2RR to formic acid. [ABSTRACT FROM AUTHOR]

The electrochemical reduction of CO2 to HCOOH is considered one of the most appealing routes to alleviate the energy crisis and close the anthropogenic CO2 cycle. However, it remains challenging to develop electrocatalysts with high activity and selectivity towards HCOOH in a wide potential window. In this regard, Ag/Bi2O2CO3 was prepared by an in situ electrochemical transformation from Ag/Bi2O3. The Ag/Bi2O2CO3 catalyst achieves a faradaic efficiency (FE) of over 90% for HCOOH in a wide potential window between −0.8 V and −1.3 V versus the reversible hydrogen electrode (RHE). Moreover, a maximum FE of 95.8% and a current density of 15.3 mA cm−2 were achieved at a low applied potential of −1.1 V. Density functional theory (DFT) calculations prove that the high catalytic activity of Ag/Bi2O2CO3 is ascribed to the fact that Ag can regulate the electronic structure of Bi, thus facilitating the adsorption of *OCHO and hindering the adsorption of *COOH. This work expands the in situ electrochemical derivatization strategy for the preparation of electrocatalysts. [ABSTRACT FROM AUTHOR]

Porous carbon materials with high electrical conductivity and superior mechanical strength have been demonstrated to be one of most promising sulfur hosts for room‐temperature sodium–sulfur (RT Na–S) batteries. However, the nonpolar surface of intact graphite lattice displays weak interaction toward the polar polysulfides, thereby resulting in the notorious shuttle effect and poor sulfur conversion kinetics. Herein, pentagon defects are designed into the graphite lattice to break the integrity of π‐conjugation, making the localized electron distribution to simultaneously enhance the polysulfide affinity and accelerate sulfur conversion kinetics. Notably, the as‐synthesized carbon materials as the sulfur host exhibit a high reversible capacity of 1275 mAh g−1 at 0.1 C after 100 cycles and long‐term cycling stability with low‐capacity decay of only 0.035% per cycle at 3 C over 600 cycles. Density functional theory calculations and electrochemical experiments confirm that pentagon defects could efficiently accelerate the chemical interaction between pentagon carbon atoms and polysulfides, and markedly lower the sulfur conversion kinetics in comparison with intact graphene. This research offers a basis for designing intrinsic pentagon defects in carbon materials as efficient catalysts for RT Na–S batteries. [ABSTRACT FROM AUTHOR]

A highly active, stable and low-cost platinum-free anode catalyst based on Ru for hydroxide exchange membrane fuel cells (HEMFCs) is hindered by the strong oxophilicity of Ru, which makes it easy to oxidize during the test. Herein, we found that Ru/CeO2(v)/C (oxygen-vacancy-rich CeO2/Ru nanoparticles supported on carbon) exhibit excellent catalytic activity with a mass activity of 8.06 A mgNM−1 and a specific activity of 2.85 mA cmNM−2, which are 19.6/20.1 and 2.3/8.4 times higher than those of Pt/C and PtRu/C, respectively. Moreover, Ru/CeO2(v)/C also exhibits excellent stability and CO tolerance in alkaline media. Experimental and theoretical studies reveal that the improved charge transfer from Ru to CeO2(v) significantly tunes the electronic structure of Ru sites and optimizes the hydrogen binding energy (HBE) of Ru, while CeO2(v) provides abundant hydroxyl adsorption sites. We attribute this enhancement to the interfacial effect, which can realize the equilibrium adsorption of hydrogen and hydroxyl groups on the interface and synergistically promote the Volmer reaction, thereby enhancing the activity and stability of the catalyst. [ABSTRACT FROM AUTHOR]

Room‐temperature sodium‐sulfur (RT Na–S) batteries are regarded as one of promising next‐generation energy storage systems owing to the high theoretical energy density (1274 Wh kg−1) and rich abundance of the raw materials. However, the sluggish redox kinetics and low electrical conductivity of sulfur (S) cathode significantly imped their practical application. Herein, a flexible carbon film implanted with single‐atomic Zn−N2 moiety (Zn‐N2/CF) is constructed as the efficient S host material to effectively improve the redox kinetics and electrical conductivity. The theoretical and experimental results show that, compared to Zn−N4 center, unsaturated Zn−N2 center with asymmetric electron distribution has significant advantages in anchoring and activating sodium polysulfides to accelerate the conversion from S8 to Na2S and reducing the reaction energy barrier of Na2S decomposition. Consequently, Zn‐N2/CF/S can retain a reversible capacity of 838.5 mAh g−1 at 0.1 A g−1 after 100 cycles, which is higher than that of Zn‐N4/CF/S (688.0 mAh g−1). Moreover, Zn‐N2/CF/S also maintains a long‐term cycling performance with a negligible capacity decay rate of 0.006% per cycle over 4000 cycles at 10 A g−1. This work provides an effective strategy to obtain the flexible carbon film implanted with unsaturated single‐atomic structure, thereby ultimately resulting in high‐performance RT Na–S batteries. [ABSTRACT FROM AUTHOR]