Single crystals of 4SC(NH2)2–Ni1-xCux Cl2(x = 0.03)(Cu-DTN) containing spin S = 1/2 Cu^2+and S = 1 Ni^2+cations are synthesized by slow evaporation methods. Structural characterization demonstrates that the Cu-DTN is of a tetrahedral structure with lattice parameter c being 9.0995 A, which is 1.32% expansion compared with that of parent material DTN due to the larger radius of the Cu ion. Direct current(DC) susceptibility measurements show that both the antiferromagnetic exchange interaction at low temperature and the large anisotropy of susceptibilities are suppressed after doping the Cu ion, which could be related to the structural distortion and the increase of the super-exchange paths in Cu-DTN.
Molybdenum disulfide (MoS_(2)) with low cost, high activity and high earth abundance has been found to be a promising catalyst for the hydrogen evolution reaction (HER), but its catalytic activity is considerably limited due to its inert basal planes. Here, through the combination of theory and experiment, we propose that doping Ni in MoS_(2) as catalyst can make it have excellent catalytic activity in different reaction systems. In the EY/TEOA system, the maximum hydrogen production rate of EY/Ni-Mo-S is 2.72 times higher than that of pure EY, which confirms the strong hydrogen evolution activity of Ni-Mo-S nanosheets as catalysts. In the lactic acid and Na_(2)S/Na_(2)SO_(3) systems, when Ni-Mo-S is used as co-catalyst to compound with ZnIn_(2)S_(4) (termed as Ni-Mo-S/ZnIn_(2)S_(4)), the maximum hydrogen evolution rates in the two systems are 5.28 and 2.33 times higher than those of pure ZnIn_(2)S_(4), respectively. The difference in HER enhancement is because different systems lead to different sources of protons, thus affecting hydrogen evolution activity. Theoretically, we further demonstrate that the Ni-Mo-S nanosheets have a narrower band gap than MoS_(2), which is conducive to the rapid transfer of charge carriers and thus result in multi-photocatalytic reaction systems with excellent activity. The proposed atomic doping strategy provides a simple and promising approach for the design of photocatalysts with high activity and stability in multi-reaction systems.
Jing ChenYumei TangShihao WangLingbin XieCheng ChangXiaolei ChengMingming LiuLonglu WangLianhui Wang
采用单一助剂硅烷偶联剂KH-560、表面活性剂硬脂酸钙和复合助剂(KH-560+硬脂酸钙)分别通过高能球磨制备片状羰基铁粉吸波材料的样品,系统地分析研究样品的微观形貌、物相、电磁参数,并通过电磁场传输线理论模拟计算吸波涂层反射损耗。结果表明:与单一助剂样品相比,复合助剂样品团聚现象明显减少,形成了平整、光滑的片状结构;模拟计算在2 mm厚度下,反射损耗小于–10 d B,复合助剂样品带宽达到1 GHz(1.4~2.4 GHz),且在2 GHz处的反射损耗峰值也达到–15 d B,均优于单一助剂样品。复合助剂的使用可以增强偶联剂和表面活性剂在片状羰基铁粉颗粒的表面包覆效果,达到更好的介电调控目的,提高低频吸波性能。