Photocatalytic studies of CdS nanoparticles assembled on carbon microsphere surfaces with different interface structures: from amorphous to graphite-like carbon

Abstract

A rapid microwave-assisted method was used for the accurate coating of CdS nanoparticles on the surface of colloidal carbon microspheres to form C/CdS hybrid microspheres, which demonstrated enhanced visible-light-photocatalytic activity for the degradation of rhodamine B (RhB). To investigate the optimal photocatalytic synergistic effect, the above as-prepared of C/CdS hybrid microspheres were treated in a tube furnace by annealing at different temperatures (from 300 to 800 uC) in a N 2 flow, which resulted in CdS nanoparticles assembled on different carbon layers (from amorphous to graphite-like carbon). The changes in FT-IR and Raman spectra that were caused by different interfaces were studied. Further, the synergic effect between CdS nanoparticles and different carbon layers, which influence the photocatalytic activity, was then investigated systematically. The results show that the photocatalytic activity of these samples was gradually enhanced as the calcination temperature increased. But compared to the sample without calcination, the photocatalytic activity decreases first and then increases. The combination of CdS and graphite-like carbon may be an ideal system to cause a rapid photoinduced charge separation and decreased possibility of recombination of electron-hole pairs by taking advantage of graphite-like carbon's unique electron transport properties, which increase the number of holes participating in the photooxidation process and enhance the photocatalytic activity.

Flexible humidity sensors composed of graphite-like carbon micro-pinecone arrays

“…2a). 24,25 The 2D band at around 2700 cm À1 characteristic of graphene 26 was not observed in the present carbonized samples produced by nanosecond pulsed UV laser irradiation. Therefore, the obtained CMP and CMC arrays consisted of graphite-like carbon.…”

One-Step Solvothermal Synthesis of Petalous Carbon-Coated Cu+-Doped CdS Nanocomposites with Enhanced Photocatalytic Hydrogen Production

“…As the most environmentally friendly energy fuel, hydrogen has been recognized as the most promising substitute for fossil fuel in the future energy system. − Since the first report of hydrogen evolution from water by Fujishima and Honda in 1972, water splitting by semiconductor photocatalysts with solar-light illumination has been considered to be one of the most important pathways for producing hydrogen . To date, numerous studies have been focused on metal sulfide semiconductor photocatalysts for photocatalytic hydrogen production owing to their excellent solar spectrum responses and high photoactivities. , Among them, cadmium sulfide (CdS) has been considered to be a highly effective visible-light-responsive photocatalyst for photocatalytic hydrogen production as a result of its optimal band gap of around 2.4 eV and the suitable potential of its conduction band (−0.9 V vs normal hydrogen electrode). − Unfortunately, an inherent drawback of pristine CdS is the photocorrosion effect under visible-light illumination in which the S 2– ion can be oxidized by photogenerated holes and the Cd 2+ ion is leached. − In general, this obstacle can be overcome by promoting the separation efficiency of photogenerated electrons and holes at the CdS surface.…”

One-step hydrothermal synthesis of cobalt and potassium codoped CdSe quantum dots with high visible light photocatalytic activity

“…Photocatalytic technology, as a prospective method, exhibits a high efficiency in oxidizing some organic compounds with high degradation ratios and low cost. [7][8][9][10] Recently, some studies on the photodegradation of antibiotics have been reported, but little has been reported on photocatalysis using quantum dots (QDs) as a photocatalyst.…”