Peng-Xiang Hou

Developing efficient and durable electrocatalysts for oxygen and hydrogen evolution reactions (OER/HER) remains fundamentally challenging due to the intrinsic trade‐off between activity and stability. We herein report a high‐entropy‐engineered strategy to stabilize single Ru atoms on FeCoNiCrMn spinel oxides to overcome the dilemma. The resulting catalyst delivers excellent bifunctional activity and stability, revealed by low overpotentials of merely 280 mV at 100 mA cm ⁻² for OER and 37 mV at 10 mA cm ⁻² for HER, a low cell voltage of 1.66 V at 1 A cm ⁻² for anion exchange membrane water electrolyzer and undamped cell performance at 1 A cm ⁻² for 1500 h. Experimental and theoretical results illustrate that single Ru atoms coordinated by O ₄ Cl species are active centers with the lowest theoretical overpotentials for OER and HER. Uniquely, reversible oxyhydroxides reconstructed from spinel oxides occur in the OER process. Meanwhile, Ru single atoms anchored on the oxyhydroxides has much higher dissolution potential than RuO ₂ and catalyzes OER following the stable adsorbate evolution mechanism pathway, resulting in excellent stability. This work highlights high‐entropy engineering for stabilizing and activating single‐atom catalysts, offering new insights into rational design of advanced catalysts for future sustainable energy device development.

Developing efficient and durable electrocatalysts for oxygen and hydrogen evolution reactions (OER/HER) remains fundamentally challenging due to the intrinsic trade‐off between activity and stability. We herein report a high‐entropy‐engineered strategy to stabilize single Ru atoms on FeCoNiCrMn spinel oxides to overcome the dilemma. The resulting catalyst delivers excellent bifunctional activity and stability, revealed by low overpotentials of merely 280 mV at 100 mA cm ⁻² for OER and 37 mV at 10 mA cm ⁻² for HER, a low cell voltage of 1.66 V at 1 A cm ⁻² for anion exchange membrane water electrolyzer and undamped cell performance at 1 A cm ⁻² for 1500 h. Experimental and theoretical results illustrate that single Ru atoms coordinated by O ₄ Cl species are active centers with the lowest theoretical overpotentials for OER and HER. Uniquely, reversible oxyhydroxides reconstructed from spinel oxides occur in the OER process. Meanwhile, Ru single atoms anchored on the oxyhydroxides has much higher dissolution potential than RuO ₂ and catalyzes OER following the stable adsorbate evolution mechanism pathway, resulting in excellent stability. This work highlights high‐entropy engineering for stabilizing and activating single‐atom catalysts, offering new insights into rational design of advanced catalysts for future sustainable energy device development.

The incorporation of electrothermal films into smart windows has been of intense research interest in developing highly conductive transparent films. However, achieving a high optical transparency and exceptional electrothermal performance simultaneously remains a great challenge. We reported a transparent conductive single-wall carbon nanotube (SWCNT) film comprised of highly-crystalline and long SWCNTs in small bundles. The SWCNT film with an average bundle diameter of 7.1 nm had a low sheet resistance of 26 Ω/□ at a transmittance of 82%, and had a constant temperature of 102 °C at a low applied voltage of 20 V. Integrating this transparent heating film with thermochromic materials enabled the fabrication of a flexible smart window with thermally triggered dynamic transparency. The device has a broad reversible visible light transparency range (~ 78%) and excellent cycling stability.

Miniaturized and wearable optical communication technology is playing a vital role in a wide range of applications, including environmental and physiological monitoring systems, as well as remote sensing systems. However, it is difficult to manufacture efficient and flexible light emitters and detectors due to the intrinsic limitations of conventional semiconductors. We report a flexible and broadband carbon nanotube (CNT)‐based optoelectronic device that consists of a CNT fiber emitter and a Bi ₂ Te ₃ /CNT film detector. The 1D CNT fiber significantly increases thermal emission by minimizing energy loss, while the 2D Bi ₂ Te ₃ /CNT‐film efficiently detects the emitted light, because of its high light absorption and conversion capabilities. As a result, the constructed optoelectronic device has a record‐high quality factor of 2.8 × 10 ⁵ S A m ⁻¹ W ⁻¹ , which is an order of magnitude higher than that of reported carbon‐based devices. A minimized and wearable optical communication system was constructed, which enables data transmission between a spun fiber emitter and a film detector. When integrated with wet‐spinning equipment for the manufacture of CNT‐fibers, it enabled the in situ testing of the quality of the fibers.

Single wall carbon nanotube (SWCNT)/Si heterojunction photodetectors have the advantages of high photoresponse ability and simple structure, however, their detection wavelength range are usually lower than 1100 nm, which limits their application in the infrared band. We report a SWCNT/Cu/Si photodetector with both a high photoresponse and a detection range up to the infrared band by depositing a Cu nanoparticles (NPs) layer between a SWCNT film and a n-Si substrate. It was found that the Cu NPs produce strong surface plasmon resonance (SPR) under laser irradiation, which breaks through the limitation of Si band gap and greatly improves the photoresponse of the SWCNT/Cu/Si photodetector in the near infrared band. The responsivity (R) of the photodetector in the wavelength range of 1850–1200 nm reached 2.2–14.15 mA/W, which is the highest value in the reported plasmon enhanced n-Si based photodetectors, and about 20,000 times higher than that of a SWCNT/Si photodetector. Its R value for 1550 nm wavelength used in optical communications reached ~ 8.2 mA/W, which is 64% higher than the previously reported values of commonly used photodetectors. We attribute the significant increase to the strong SPR and low Schottky barrier of Cu with n-Si, which facilitates the generation and transfer of the carriers.

Single-metal-site catalysts have recently aroused extensive research in electrochemical energy fields such as zinc-air batteries and water splitting, but their preparation is still a huge challenge, especially in flexible catalyst films. Herein, we propose a sublimation strategy in which metal phthalocyanine molecules with defined isolated metal-N₄ sites are gasified by sublimation and then deposited on flexible single-wall carbon nanotube (SWCNT) films by means of π-π coupling interactions. Specifically, iron phthalocyanine anchored on the SWCNT film prepared was directly used to boost the cathodic oxygen reduction reaction of the zinc-air battery, showing a high peak power density of 247 mW cm^-2. Nickel phthalocyanine and cobalt phthalocyanine were, respectively, stabilized on SWCNT films as the anodic and cathodic electrocatalysts for water splitting, showing a low potential of 1.655 V at 10 mA cm^-2. In situ Raman spectra and theoretical studies demonstrate that highly efficient activities originate from strain-induced metal phthalocyanine on SWCNTs. This work provides a universal preparation method for single-metal-site catalysts and innovative insights for electrocatalytic mechanisms.

Bifacial perovskite solar cells have shown great promise for increasing power output by capturing light from both sides. However, the suboptimal optical transmittance of back metal electrodes together with the complex fabrication process associated with front transparent conducting oxides have hindered the development of efficient bifacial PSCs. Here, we present a novel approach for bifacial perovskite devices using single-walled carbon nanotubes as both front and back electrodes. single-walled carbon nanotubes offer high transparency, conductivity, and stability, enabling bifacial PSCs with a bifaciality factor of over 98% and a power generation density of over 36%. We also fabricate flexible, all-carbon-electrode-based devices with a high power-per-weight value of 73.75 W g⁻¹ and excellent mechanical durability. Furthermore, we show that our bifacial devices have a much lower material cost than conventional monofacial PSCs. Our work demonstrates the potential of SWCNT electrodes for efficient, stable, and low-cost bifacial perovskite photovoltaics.

Carbon nanotube (CNT) fibers have great promise for constructing multifunctional fabrics with high electrical conductivity, good electro-heating ability, excellent flexibility, and a low density. However, the inter-fiber contacts in the fabric greatly reduce these advantages and limit their application. Herein, a simple pressure-fusing method to fabricate single-wall CNT (SWCNT) fiber non-woven fabrics (NWFs) that are composed of interconnected SWCNT fibers with fused joints is reported, which have good flexibility, a low density of 0.46 g/cm³, a high electrical conductivity of 3.7 × 10⁵ S/m, and a record high specific electrical conductivity of 803 (S·m²)/kg. They also showed excellent electrical heating ability, so that a temperature of ∼ 160 °C was rapidly reached at a low voltage of 2 V. Combined with their low density, the SWCNT fiber NWFs are promising for use as a heating unit for low temperature battery protection and de-icing applications.