SnS_2 nanosheets arrays sandwiched by N-doped carbon and TiO_2 for high-performance Na-ion storage

In this paper, SnS_2 nanosheets arrays sandwiched by porous N-doped carbon and TiO_2(TiO_2@SnS_2@N-C) on flexible carbon cloth are prepared and tested as a free-standing anode for high-performance sodium ion batteries. The as-obtained TiO_2@SnS_2@N-C composite delivers a remarkable capacity performance(840 mA h g^(-1) at a current density of 200 mA g^(-1)), excellent rate capability and long-cycling life stability(293 mA h g^(-1) at 1 A g^(-1) after 600 cycles). The excellent electrochemical performance can be attributed to the synergistic effect of each component of the unique hybrid structure, in which the SnS_2 nanosheets with open framworks offer high capacity, while the porous N-doped carbon nanoplates arrays on flexible carbon cloth are able to improve the conductivity and the TiO_2 passivation layer can keep the structure integrity of SnS_2 nanosheets.

新型二维铜族硫族化合物MX(M=Cu,Ag,Au;X=S,Se,Te):二维极化金属与可见光催化剂

二维过渡金属硫族化合物因其优异的特性和广泛的应用前景而受到众多研究领域的关注.本文报道了一类具有极化金属和可见光催化特性的新型二维铜族硫族化合物MX (M=Cu,Ag,Au;X=S,Se,Te).金属性ι-CuS、ι-AgS和ι-AgTe的原子结构是面外反演非对称的,其底部和顶部具有不同功函数.因而这些金属单层与石墨烯形成异质结可使其功函数从4.35 eV扩展到3.87–5.04 eV.半导体性β-AgSe和α-AuTe/α-AuS/α-AuSe在pH=0/7下仅仅满足H+/H_(2)和H_(2)O/O_(2)反应的带边要求.进一步,α-AuSe/α-AuTe异质结作为Z型光催化剂在可见光驱动的水分解中具有极大的应用潜力,其具有合适的带边位置、增强的光吸收以及高太阳能-氢能转换效率(20.47%).这些优异的性能使二维铜族硫族化合物MX成为二维过渡金属硫族化合物研究领域的重要组成部分,有望得到理论和实验的密切关注.