Conversion of naturally abundant nitrogen to ammonia is a key (bio)chemical process to sustain life and represents a major challenge in chemistry and biology. Electrochemical reduction is emerging as a sustainable strategy for artificial nitrogen fixation at ambient conditions by tackling the hydrogen- and energy-intensive operations of the Haber–Bosch process. However, it is severely challenged by nitrogen activation and requires efficient catalysts for the nitrogen reduction reaction. Here we report that a boron carbide nanosheet acts as a metal-free catalyst for high-performance electrochemical nitrogen-to-ammonia fixation at ambient conditions. The catalyst can achieve a high ammonia yield of 26.57 μg h–1 mg–1cat. and a fairly high Faradaic efficiency of 15.95% at –0.75 V versus reversible hydrogen electrode, placing it among the most active aqueous-based nitrogen reduction reaction electrocatalysts. Notably, it also shows high electrochemical stability and excellent selectivity. The catalytic mechanism is assessed using density functional theory calculations.

Atherosclerosis is characterized by the accumulation of lipids within the arterial wall. Although activation of TRPV1 cation channels by capsaicin may reduce lipid storage and the formation of atherosclerotic lesions, a clinical use for capsaicin has been limited by its chronic toxicity. Here we show that coupling of copper sulfide (CuS) nanoparticles to antibodies targeting TRPV1 act as a photothermal switch for TRPV1 signaling in vascular smooth muscle cells (VSMCs) using near-infrared light. Upon irradiation, local increases of temperature open thermo-sensitive TRPV1 channels and cause Ca2+ influx. The increase in intracellular Ca2+ activates autophagy and impedes foam cell formation in VSMCs treated with oxidized low-density lipoprotein. In vivo, CuS-TRPV1 allows photoacoustic imaging of the cardiac vasculature and reduces lipid storage and plaque formation in ApoE−/− mice fed a high-fat diet, with no obvious long-term toxicity. Together, this suggests CuS-TRPV1 may represent a therapeutic tool to locally and temporally attenuate atherosclerosis.

The synthesis of NH3 is mainly dominated by the traditional energy-consuming Haber–Bosch process with a mass of CO2 emission. Electrochemical conversion of N2 to NH3 emerges as a carbon-free process for the sustainable artificial N2 reduction reaction (NRR), but requires an efficient and stable electrocatalyst. Here, we report that the Mo2C nanorod serves as an excellent NRR electrocatalyst for artificial N2 fixation to NH3 with strong durability and acceptable selectivity under ambient conditions. Such a catalyst shows a high Faradaic efficiency of 8.13% and NH3 yield of 95.1 μg h–1 mg–1cat at −0.3 V in 0.1 M HCl, surpassing the majority of reported electrochemical conversion NRR catalysts. Density functional theory calculation was carried out to gain further insight into the catalytic mechanism involved.

Bifunctional electrocatalysts that can boost energy-related reactions are urgently in demand for pursual of dual and even multiple targets towards practical applications such as energy conversion, clean fuel production and pollution treatment.

MoO3 nanosheets act as an efficient electrocatalyst for N2 fixation to NH3 with excellent selectivity at ambient conditions. In 0.1 M HCl, they show high activity with an NH3 yield of 4.80 × 10−10 mol s−1 cm−2 (29.43 μg h−1 mgcat.−1) and a faradaic efficiency of 1.9%.

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A highly attractive, but still a key challenge, is the development of earth-abundant electrocatalysts for efficient NH3 electrosynthesis via the N2 reduction reaction (NRR). In this communication, we report the development of a Mo2N nanorod as a highly efficient and selective NRR electrocatalyst for artificial N2 fixation in acidic electrolytes under ambient conditions. In 0.1 M HCl, this catalyst achieved a high Faradaic efficiency of 4.5% with a NH3 yield of 78.4 μg h-1 mgcat.-1 at -0.3 V vs. a reversible hydrogen electrode, thus outperforming most reported NRR electrocatalysts under ambient conditions and some under harsh conditions. Density functional theory calculations revealed that the free energy barrier of the potential determining step of NRR on MoO2 decreases dramatically after nitrogenization.

§ Longcheng Zhang and Jie Liang contributed equally to this work. Benzoate anions-intercalated NiFe-LDH nanosheet on carbon cloth (BZ-NiFe-LDH/CC) behaves as a highly efficient and durable electrocatalyst for alkaline seawater oxidation. In alkaline seawater, it attains the current density of 500 mA cm -2 at a low overpotential of 610 mV for 100-h uninterrupted electrolysis with no obvious structural change, reflecting significantly boosted activity and resistance toward chlorine species corrosion.