Yuanqing Sun

Pt is a widely recognized catalyst for the alkaline hydrogen evolution reaction (HER), but its high cost and scarcity hinder its large‐scale industrial application to date. In this work, we report an S, N co‐doped carbon (SNC) supported amorphous nanocluster (NCs) composite catalyst (Pt _n +Pt ₁ ‐SNC/NF) composed of Pt NCs encircled by a multitude of Pt single atoms (SAs). The Pt _n +Pt ₁ ‐SNC/NF was synthesized by an etching method using nitrogen‐doped carbon‐coated nickel foam (ppy/NF) as the substrate. Compared to commercial Pt/C, the catalyst exhibits a low HER overpotential (only 19 mV at 10 mA cm ⁻² ) in 1 M KOH, a mass activity nearly four times higher than that of commercial Pt/C (115.4 A mg ⁻¹ Pt at 100 mV), and excellent stability under high current density (up to 500 h). Systematic spectroscopic characterization reveals that the defective carbon substrate adsorbs and activates water molecules, leading to an increased relative concentration of activated water on the catalyst surface. The Pt SAs promote the adsorption and transfer of water molecules to the NCs surface, while the Pt NCs facilitate subsequent water dissociation and OH ⁻ desorption. The theoretical findings align well with experimental outcomes. This work offers a promising strategy to develop high‐efficiency and low‐cost noble metal‐based electrocatalysts toward practical hydrogen evolution.

UV irradiation constructs the Cu ₂ O sub-nanocluster and oxygen-rich TiO _{2+ x} interface, enabling efficient and durable electrochemical conversion of nitrate to ammonia at industrial-scale current densities.

In the realm of water electrolysis catalysts, supported platinum‐based catalysts have consistently exhibit superior catalytic activity. However, the catalytic mechanisms of platinum species with varying oxidation states, particularly the higher oxidation states, remain elusive. Herein, an UV light induced reactive oxygen species (ROS) strategy is developed to construct uniformly dispersed PtOx nanoclusters on nitrogen‐doped hollow carbon spheres (PtOx/NHCS). The in‐situ Raman spectroscopy and density functional theory (DFT) calculations reveal that the nitrogen‐doped carbon matrix optimizes the proton transfer pathways through the adsorption of oxygen‐containing species. Additionally, the unique electronic structure of the Pt–O units in the PtOx clusters accelerated the transformation of proton adsorption and desorption capabilities at the active sites. Therefore, the engineered catalyst demonstrates exceptional bifunctionality for hydrogen electrode reactions, delivering HER current density of 10 mA cm ⁻² with ultralow overpotentials of 17 mV (alkaline) and18 mV (acidic) while simultaneously achieving superb HOR mass activity of 1345.56 mA mg ⁻¹ Pt at η = 50 mV. Meanwhile, the observed kinetic reciprocity between HER and HOR operations provides compelling evidence for the possibility of the proton transfer mechanism.

Ammonia plays an irreplaceable role in agricultural production and also is an important chemical raw material and energy carrier. Developing a catalyst for the electrochemical NO₃⁻ reduction reaction (NO₃RR) to synthesize ammonia is crucial for energy, food security and pollution control. Herein, by adjusting the Cu/Ni ratio, we report a simple impregnation and calcination method to synthesize a N-doped bamboo-like carbon nanotube (CNT)-encapsulated CuNi alloy catalyst (Cu₇Ni₃-CNT). Cu₇Ni₃-CNT reveals an excellent ammonia synthesis performance, which has the highest Faraday efficiency (FE, 99.18%) at -0.8 V vs. RHE, along with an ammonia production rate of 20.90 mg cm^-2 h^-1. In addition, the highest ammonia production rate of Cu₇Ni₃-CNT can reach 23.21 mg cm^-2 h^-1, with a high FE (90.80%) at -1.0 V vs. RHE. At the same time, the electrocatalyst displays exceptional stability, which can operate steadily for 400 hours at 300 mA cm^-2. The high catalytic activity and excellent stability derive from catalyst structure and the synergistic effect between Cu₇Ni₃ alloy and encapsulating bamboo-like CNT. The incorporation of Ni enhances the intrinsic activity of Cu for NO₃RR. CNT endows the catalyst with a larger specific surface area, more exposed active sites to further improve the apparent activity., and higher stability. The internal cavity of CNT also contributes to the enrichment of nitrate. Furthermore, In-situ Raman spectroscopy and density function theory (DFT) calculations reveal that Cu in the alloy can be effectively adjust the adsorption energy of *NO₃ by Ni element and increase the activity of *H as the reduction driving force, thereby improving the intrinsic activity of NO₃RR.

Adjusting the interfacial interaction between metal and support in loaded electrocatalysts is critical for enhancing the performance of electrocatalytic hydrogen evolution in both acidic and basic media, yet it continues to pose a significant challenge. This study proposes a sulfur doping strategy aimed at enhancing the strong metal–support interaction (SMSI) of ultra-small platinum (Pt) nanoparticles (NPs) uniformly encapsulated within nitrogen–sulfur co-doped carbon materials (NSC). This approach modulates the coordination environment and electronic structure of the Pt material, leading to substantial charge redistribution at the closely interfaced Pt–carbon layer heterojunction, thereby facilitating a rapid hydrogen evolution reaction (HER). The Pt/NSC exhibits excellent intrinsic activity at 1.0 M KOH (η₁₀ = 17.8 mV, 30.59 mV dec⁻¹) and 0.5 M H₂SO₄ (η₁₀ = 10.2 mV, 18.85 mV dec⁻¹), demonstrating a lower overpotential and a reduced Tafel slope, significantly outperforming the commercial Pt/C catalyst. Furthermore, owing to the exceptional stability of NSC and the pronounced confinement effect at the interface, Pt/NSC exhibits robust resistance to both acid and alkaline corrosion. Experimental and theoretical investigations reveal that the strong interfacial coupling effect can facilitate spontaneous electron transfer from the support to the Pt NPs. The electron-rich Pt NPs significantly enhance the efficiency of charge transfer and optimize the chemisorption behavior of intermediates, thereby improving the kinetics of hydrogen production.

In response to alleviate the escalating environmental pollution and energy scarcity, the development of a cost-effective, efficient, and stable bifunctional oxygen reduction/evolution reaction (ORR/OER) electrochemical catalyst for new energy conversion devices holds significant value. In this context, we present a two-step hydrothermal/annealing synthesis approach of CoFe alloy nanoparticles on nitrogen-doped ultra-thin carbon nanosheets as an excellent ORR/OER bifunctional catalyst. The hydrothermal process facilitates the intercalation of CoFe layered double hydroxide (CoFe LDH) onto the nitrogen-doped ultra-thin carbon layer, followed by an in-situ transformation into carbon-coated nano-alloy particles (Co₃Fe₇@NCNS) during high-temperature annealing. Co₃Fe₇@NCNS exhibits exceptional ORR activity (E_onset = 0.962 V, E_1/2 = 0.869 V) and bifunctional electrocatalytic performance, accompanied by a low reversible overvoltage of 0.82 V. Combining X-ray Absorption Fine Structure (XAFS) spectroscopy and Density Functional Theory (DFT) calculations, we elucidate that the strong interactions between the synthesized Co₃Fe₇@NCNS alloy particles optimize the adsorption energy of oxygen intermediates, thereby playing a crucial role in enhancing catalytic activity. Furthermore, the Co₃Fe₇@NCNS-equipped Zn-air battery demonstrates a higher open-circuit voltage of 1.46 V and remarkable power density of 202.8 mW cm^-2. It also exhibits excellent cycling stability, with a high specific capacity of 779.2 mA h g^-1, outperforming that of the Pt/C-RuO₂ counterpart.

We prepared a novel red fluorescence-emitting DPA-Au/Cu NCs@CS fluorescent composite film with great stability, selectivity, and sensitivity that can be utilized as a fluorescent probe to detect Cr( vi ) in real time with a detection limit of 0.26 ppb.

HAuCl ₄ and MnCl ₂ are used as raw materials and sulfhydryl polymer as the ligand to synthesize Au/Mn NDs through a one-step method. The prepared Au/Mn NDs integrate CT/MRI/FI imaging and PTT against tongue cancer in a single nanoagent.

Herein, the hierarchical porous catalyst of 3-dimensional ordered macro-mesoporous (3DOMM) Al₂O₃ supported active PtSn nanoparticles (NPs) was prepared by the combined synthesized path of evaporation-induced self-assembly with colloid crystal template (EISA-CCT) methods. The hierarchical macro-mesoporous composite structure can markedly increase the specific surface area, accommodate the diffusion of propene, and decrease the number of surface acid sites. In addition, the special surface property and pore structure of 3DOMM-Al₂O₃ can modify the interaction between metals and substrates, as well as stabilize the metal nanoparticle, which promotes the formation of a highly active and stable PtSn phase. The PtSn/3DOMM-Al₂O₃ catalyst exhibits higher productivity and stability than PtSn/Al₂O₃ catalysts with macropore and mesopore structures. The PtSn/3DOMM-Al₂O₃ catalyst displays the best catalytic performance with propylene selectivity over 95% at a propane conversion of 33.9%. The study of the ordered hierarchical porous structure of PtSn/3DOMM-Al₂O₃ catalysts can contribute to obtaining improved catalysts in industrial processes.