Mesoporous Semiconductive Bi2Se3 Films

Bi₂Se₃ is a semiconductive material possessing a bandgap of 0.3 eV, and its unique band structure has paved the way for diverse applications. Herein, we demonstrate a robust platform for synthesizing mesoporous Bi₂Se₃ films with uniform pore sizes via electrodeposition. Block copolymer micelles act as soft templates in the electrolyte to create a 3D porous nanoarchitecture. By controlling the length of the block copolymer, the pore size is adjusted to 9 and 17 nm precisely. The nonporous Bi₂Se₃ film exhibits a tunneling current in a vertical direction of 52.0 nA, but upon introducing porosity (9 nm pores), the tunneling current increases significantly to 684.6 nA, suggesting that the conductivity of Bi₂Se₃ films is dependent on the pore structure and surface area. The abundant porous architecture exposes a larger surface area of Bi₂Se₃ to the surrounding air within the same volume, thereby augmenting its metallic properties.

Aqueous-phase Selective Hydrogenation of Furfural to Furfuryl Alcohol over Ordered-mesoporous Carbon Supported Pt Catalysts Prepared by One-step Modified Soft-template Self-assembly Method

Ordered mesoporous carbon (OMC) has attracted a great deal of attention as catalyst support due to their tunable morphological and textural properties. In this study, the characteristics and catalytic properties of OMC-supported Pt catalysts prepared by one-step modified soft-template self-assembly method (Pt/OMC-one-pot) were compared to the Pt impregnated on OMC, activated carbon (AC), and non-uniform meso/macroporous carbon (MC) in the selective hydrogenation of furfural to furfuryl alcohol (FA) under mild conditions (50°C, 2 MPa H₂). Larger Pt particle size (~4 nm) was obtained on the Pt/OMC-onepot comparing to all the impregnated ones, in which the Pt particle sizes were in the range 0.5 - 2 nm. Reduction step was not necessary on the Pt/OMC-one-pot and among the catalysts studied, the Pt/OMCone-pot exhibited the highest furfural conversion and FA selectivity under aqueous conditions. The use of methanol as the solvent resulted in the formation of solvent product (2-furaldehyde dimethyl acetal) instead. The amount of Pt being deposited, location of Pt particles, and metal-support interaction strongly affected recyclability of the catalysts because some larger size Pt particles with weak metal-support interaction could be leached out during the liquid-phase reaction, rendering similar catalytic performances of the various porous carbon supported catalysts after the 3^rd cycle of run.