Synthesis,Performance And Application Of Transiton Metal Sulfides

Transition metal sulfides with special 3d valence electron shell and abundant elememts have become hot topics and drawn more and more attention in the field of nanomaterial and nanotechnoloty. Transiton metal sulfides have been extensively applied for catalysts, batteries, supercapacitor, lubricant, optics and biomedicine, due to their special physical and chemical properties. As a typical representative of two-dimensional layered transition metal sulfides, molybdenum disulfide (MoS2) is inexpensive and abundant on the earth, which has been widely investigated andproved to be a promising alternative to noble metal catalysts such as platinum for hydrogen evolution reaction (HER). In addition, silver sulfide (Ag2S) semiconductor quantum dots have enormous emittion in the second near-infrared region (NIR-Ⅱ), which is desirable and promising as a fluorescent probe in bioapplications. In this work, new types of MoS2 and Ag2S nanocrystals have been controllable synthesized via hydrothermal methods, and their performance and applications have been accessed.1、The edge sites of MoS2 nanostructures have been determined as the active sites for hydrogen evolution reaction (HER). Here, we report a novel strategy to synthesize the ultrasmall donut shape Cu7S4@MoS2 heteronanoframes with abundant active MoS2 edge sites and great crystalline. These nanoframes generate a cathode current density of 10 and 200 mA/cm2 at the overpotentials of 133 and 206 mV, respectively. These nanoframes also show high exchange current density and small Tafel slope of 48mV/dec. The strategy of controllable enriching active sites to enhance effect of the HER activity may provide some guidelines for the design and synthesis of efficient and non-precious nanocatalysts.2、Ultrasmall Ag2S nanocrystals with an average diameter of approximately 5.4 nm have been synthesized via microwave reaction. The as-prepared Ag2S quantum dots exhibited bright Near-Infrared photo-luminescence (Em=1200nm). After surface coating with polysuccinimide (PSI) and functionalizing with RGD and DOX, these fabricated Ag2S nanoparticles showed good biocompatibility, outstanding in vivo imaging of tumor sites as well as effective ablation of cancer cells, indicating the great potential as multifunctional nanoprobes for tumor imaging and drug delivery.