Xiaoyu Chen,Xiaodong Li,Zhilin Chen,Binqian Wu,Zhuoran Jia,Feilong Gong
Constructing electrocatalysts with heterogeneous interfaces is of great significance for improving the performance of electrocatalytic hydrogen production . In this work, CuWO 4 ·2H 2 O–CuO (P-CWOC) was synthesized by hydrothermal method , and spherical porous CuWO 4 –CuO (CWOC) was obtained through annealing treatment. The size of CuWO 4 –CuO can be controlled from 72 to 221 nm by regulating the supersaturation of the solution. Among them, CuWO 4 –CuO with a particle size of 72 nm (CWOC-72) possesses the most oxygen vacancies and the largest specific surface area . The W atom in the heterostructure of CuWO 4 and CuO can affect the electronic structure of Cu atoms, and the presence of oxygen vacancies is beneficial for increasing the surface oxygen affinity of the composite material. Benefitting from the largest number of oxygen vacancies and the largest specific surface area, the CWOC-72 own the best catalytic performance compared to the other four catalysts. The overpotential at a current density of 10 mA cm −2 is 121 mV, and the Tafel slope is 70 mV·dec −1 . Its excellent stability was confirmed by chronoamperometry , in-situ XRD , and in-situ Raman spectroscopy , and its alkaline HER performance is superior to most CuO-based catalysts.
Ying Lei,Jianyang Zhang,Haoquan Zhuang,Tao Yin,Pengcheng Lin
High-power consumption causes excessive heat of 5G devices, compromising performance and lifespan. Phase change materials (PCMs) enable passive, constant-temperature thermal management but suffer from leakage and low thermal conductivity, limiting their application. In this work, a strategy of heat transfer enhancement in thermal energy storage gels by size engineering of boron nitride (BN) towards 5G thermal management is proposed. Specifically, tetradecanol (TD), whose thermal storage temperature is close to the thermal management temperature of electronic devices, is selected as the working medium. Based on the van der Waals force and hydrogen bond between TD and styrene-ethylene-butylene-styrene (SEBS), TD@SEBS@BN gels (TSBGs) with suppressed leakage are formed. The enthalpy of the TSBG is as high as 128.12 J g −1 , stably storing heat at around 35.84°C. The synergistic enhancement of heat transfer of TSBGs by large/small-sized BN is studied. An efficient heat transfer network has been established by coupling large-sized BN (average 30 μm) and small-sized BN (average 1 μm). The thermal conductivity of TSBG is increased from 0.304 W m −1 K −1 to a high value of 0.966 W m −1 K −1 (an increase of 317.76%). The efficient thermal management of 5G electronic components is finally realized using TSBGs.
危险品化学品经营许可证（带存储）