WC nanorods or WC nanodots are prepared via an easy,shape-controllable and large-scale preparation technique.Results reveal that each of the WC nanorods and WC nanodots has a peroxidase-like activity.Besides,the perox...WC nanorods or WC nanodots are prepared via an easy,shape-controllable and large-scale preparation technique.Results reveal that each of the WC nanorods and WC nanodots has a peroxidase-like activity.Besides,the peroxidase-like activity of WC is the first time to be demonstrated.The catalytic efficiency of WC nanorods is much higher than that of WC nanodots and chemical condition range of WC can be wider than that of WC,which indicates that WC is likely to be used as artificial mimetic peroxidase or in-situ amplified colorimetric immunoassay.展开更多
Large scale tungsten nanowires and tungsten nanodots are prepared in a controllable way. The preparation is based on mechanisms of chemical vapor transportation and phase transformation during the reduction of ammoniu...Large scale tungsten nanowires and tungsten nanodots are prepared in a controllable way. The preparation is based on mechanisms of chemical vapor transportation and phase transformation during the reduction of ammonium metatungstate (AMT) in H2. The AMT is first encapsulated into the hollow core of nanostructured carbon with hollow macroporous core/mesoporous shell (NC-HMC/MS) and forms nanorods, which are the precursors of both tungsten nanowires and tungsten nanodots. Just by controlling H2 flow rate and heating rate in the reduction process, the AMT nanorods could turn into nanowires (under low rate condition) or nanodots (under high rate condition). Besides, via heat treatment at 1200 ℃, the as-obtained nano-sized tungsten could convert into W2C nanorods or WC nanodots respectively. Furthermore, the diameter of the as-obtained tungsten or tungsten carbide is confined within 50 nm by the NC-HMC/MS, and no agglomeration appears in the obtained nanomaterials.展开更多
文摘WC nanorods or WC nanodots are prepared via an easy,shape-controllable and large-scale preparation technique.Results reveal that each of the WC nanorods and WC nanodots has a peroxidase-like activity.Besides,the peroxidase-like activity of WC is the first time to be demonstrated.The catalytic efficiency of WC nanorods is much higher than that of WC nanodots and chemical condition range of WC can be wider than that of WC,which indicates that WC is likely to be used as artificial mimetic peroxidase or in-situ amplified colorimetric immunoassay.
文摘Large scale tungsten nanowires and tungsten nanodots are prepared in a controllable way. The preparation is based on mechanisms of chemical vapor transportation and phase transformation during the reduction of ammonium metatungstate (AMT) in H2. The AMT is first encapsulated into the hollow core of nanostructured carbon with hollow macroporous core/mesoporous shell (NC-HMC/MS) and forms nanorods, which are the precursors of both tungsten nanowires and tungsten nanodots. Just by controlling H2 flow rate and heating rate in the reduction process, the AMT nanorods could turn into nanowires (under low rate condition) or nanodots (under high rate condition). Besides, via heat treatment at 1200 ℃, the as-obtained nano-sized tungsten could convert into W2C nanorods or WC nanodots respectively. Furthermore, the diameter of the as-obtained tungsten or tungsten carbide is confined within 50 nm by the NC-HMC/MS, and no agglomeration appears in the obtained nanomaterials.