Fabrication of Core‐Shell Nanocolloids with Various Core Sizes to Promote Light Capture for Green Fuels

Abstract

Core-shell nanocolloids with tailored physical and chemical merits hold attractive potential for energy-related applications. Herein, core-shell nanocolloids composed of zinc/copper sulfide (ZnS/CuS x) shells and silica (SiO 2) cores were fabricated by a template-engaged synthetic method. Interestingly, the sizes of SiO 2 cores can be tuned by different sulfurization time. In virtue of the light scattering and reflection on the SiO 2 surface, the efficiencies of light capture by ZnS/Cu 2 S shells were highly dependent on the SiO 2 sizes. The as-fabricated SiO 2 @ZnS/Cu 2 S with a core size of 205 nm exhibited the highest and broadest absorption within a light wavelength of 380-700 nm. In virtue of the structural and componential features of these nanocolloids, maximum photocatalytic hydrogen (H 2) production rates of 2968 and 1824 μmol h À 1 g À 1 under UV-vis and visible light have been delivered, respectively. This work may provide some evidence for the design and fabrication of core-shell nanomaterials to convert solar energy to green fuels.

Supported nanostructured photocatalysts: the role of support-photocatalyst interactions

“…The authors demonstrated that variations in core sizes and void space percentage result in strikingly different visible light absorption properties. The SiO 2 @ZnS/CuS x sample with 205 nm core size showed the highest light-harvesting capacity and, consequently, the highest photocatalytic H 2 production yield [139]. This report provides interesting insights into how core-shell (or yolk-shell) supported catalyst nanostructures can be designed to enhance light capture properties, hence the performance of photocatalysts for environmental and energy applications.…”

“…As previously mentioned, spherical silica supports may also improve photocatalytic performance by enhancing optical absorption through multiple scattering steps in the silicaphotocatalyst interface, thus improving light confinement and utilization in the photoactive semiconducting layer. In addition to the already mentioned SiO 2 @TiO 2 system, such improved optical properties were recently demonstrated in other systems involving emerging visible light photocatalysts, such as SiO 2 @g-C 3 N 4 [137] , SiO 2 @g-C 3 N 4 /CdS [138] and SiO 2 @ZnS/CuS X [139], among others. The study by Ren et al [139] shows the optimization of light-scattering properties of silica-supported core-shell metal sulfides for enhanced photocatalytic production of H 2 (Fig.…”

“…In addition to the already mentioned SiO 2 @TiO 2 system, such improved optical properties were recently demonstrated in other systems involving emerging visible light photocatalysts, such as SiO 2 @g-C 3 N 4 [137] , SiO 2 @g-C 3 N 4 /CdS [138] and SiO 2 @ZnS/CuS X [139], among others. The study by Ren et al [139] shows the optimization of light-scattering properties of silica-supported core-shell metal sulfides for enhanced photocatalytic production of H 2 (Fig. 8a).…”

“…Fig.8SiO 2 @ZnS/CuS x nanoparticles for enhanced visible-light photocatalytic H 2 evolution: a Illustrative scheme of light scattering on SiO 2 cores in SiO 2 @ZnS/CuS x , b two-step hydrothermal synthesis employed for the synthesis of SiO 2 @ZnS/CuS x photocatalysts along with the corresponding TEM images of the materials at each stage. Reprinted with permission from[139] …”

Understanding the Catalytic Kinetics of Polysulfide Redox Reactions on Transition Metal Compounds in Li–S Batteries

“…Growing social demands are driving an upgrade in the electrical and electronics industry and calling for high-energy-density energy storage systems. − Among the various candidates, lithium–sulfur (Li–S) batteries as one of the core battery technologies of the post-lithium-ion battery era have received widespread attention since their emergence in 1962, with strengths of high theoretical gravimetric energy density (2600 Wh/kg), abundant sulfur reserves, and low pollution to the environment. − Figure shows some significant milestones for Li–S batteries. − However, apart from the above advantages that could ensure their bright prospect, Li–S batteries have some drawbacks: (i) low utilization rate of sulfur, (ii) sluggish reaction kinetics, (iii) low conductivity of active sulfur (S 8 ) and discharging products (Li 2 S 2 /Li 2 S), and (iv) the shuttle effect of polysulfides. The shuttle effect is considered to be one of the most crucial reasons limiting Li–S batteries, which leads to decreased output capacity and low columbic efficiency (CE). − …”