Significant efforts have been devoted to develop efficient visible-light-driven photocatalysts for the conversion of CO2 to chemical fuels. The photocatalytic efficiency for this transformation largely depends on CO2 adsorption and diffusion. However, the CO2 adsorption on the surface of photocatalysts is generally low due to their low specific surface area and the lack of matched pores. Here we report a well-defined porous hypercrosslinked polymer-TiO2-graphene composite structure with relatively high surface area i.e., 988 m2 g−1 and CO2 uptake capacity i.e., 12.87 wt%. This composite shows high photocatalytic performance especially for CH4 production, i.e., 27.62 μmol g−1 h−1, under mild reaction conditions without the use of sacrificial reagents or precious metal co-catalysts. The enhanced CO2 reactivity can be ascribed to their improved CO2 adsorption and diffusion, visible-light absorption, and photo-generated charge separation efficiency. This strategy provides new insights into the combination of microporous organic polymers with photocatalysts for solar-to-fuel conversion.

Ligands play an important role in determining the atomic arrangement within the metal nanoclusters. Here, we report a new nanocluster [Au23−xAgx(S‐Adm)15] protected by bulky adamantanethiol ligands which was obtained through a one‐pot synthesis. The total structure of [Au23−xAgx(S‐Adm)15] comprises an Au13−xAgx icosahedral core, three Au3(SR)4 units, and one AgS3 staple motif in contrast to the 15‐atom bipyramidal core previously seen in [Au23−xAgx(SR)16]. UV/Vis spectroscopy indicates that the HOMO–LUMO gap of [Au23−xAgx(S‐Adm)15] is 1.5 eV. DFT calculations reveal that [Au19Ag4(S‐Adm)15] is the most stable structure among all structural possibilities. Benefitting from Ag doping, [Au23−xAgx(S‐Adm)15] exhibits drastically improved photocatalytic activity for the degradation of rhodamine B (RhB) and phenol under visible‐light irradiation compared to Au23 nanoclusters.

The electrical performance of MoS2 can be engineered by introducing high-κ dielectrics, while the interactions between high-κ dielectrics and MoS2 need to be studied. In this study, multilayer MoS2 field-effect transistors (FETs) with a back-gated configuration were fabricated on high-κ Al2O3 coated Si substrates. Compared with MoS2 FETs on SiO2, the field-effect mobility (μFE) and subthreshold swing (SS) were remarkably improved in MoS2/Al2O3/Si. The improved μFE was thought to result from the dielectric screening effect from high-κ Al2O3. When a HfO2 passivation layer was introduced on the top of MoS2/Al2O3/Si, the field-effect mobility was further enhanced, which was thought to be concerned with the decreased contact resistance between the metal and MoS2. Meanwhile, the interface trap density increased from 2.4×1012 eV−1cm−2 to 6.3×1012 eV−1cm−2. The increase of the off-state current and the negative shift of the threshold voltage may be related to the increase of interface traps.

This paper develops a novel ultrasonic spray-assisted solvothermal (USS) method to synthesize wrapped ZnO/reduced graphene oxide (rGO) nanocomposites with a Schottky junction for gas-sensing applications. The as-obtained ZnO/rGO- x samples with different graphene oxide (GO) contents ( x = 0–1.5 wt %) are characterized by various techniques, and their gas-sensing properties for NO 2 and other VOC gases are also evaluated. The results show that the USS-derived ZnO/rGO samples exhibit high NO 2 -sensing property at low operating temperatures (e.g., 70–130 °C) because of their high specific surface area and porous structures when compared with the ZnO/rGO sample obtained by the traditional precipitation method. The content of rGO shows an obvious effect on their NO 2 -sensing properties, and the ZnO/rGO-0.5 sample has a high response of 62 operating at 130 °C, three times that of pure ZnO. The detection limit of the ZnO/rGO-0.5 sensor to NO 2 is as low as 10 ppb under the present test condition. In addition, the ZnO/rGO-0.5 sensor shows a highly selective response to NO 2 gas when compared with organic vapors and other inflammable or toxic gases. The theoretical and experimental analyses indicate that the enhancement in NO 2 -sensing performance of the ZnO/rGO sensor is attributed to the formation of wrapped ZnO/rGO Schottky junctions.

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The nanosheets TiO 2 /g-C 3 N 4 hybrid material with efficient visible-light photocatalytic activity was prepared by a facile solvothermal method. The as-prepared TiO 2 /g-C 3 N 4 nanosheets composite was thoroughly characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, N 2 adsorption-desorption analysis, UV-Vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. As evaluated by the degradation of methylene blue under visible light irradiation, TiO 2 /g-C 3 N 4 hybrid composites exhibit much higher photocatalytic activity than pristine g-C 3 N 4 and TiO 2 , respectively. The significant enhancement in photodegradation activity over the TiO 2 /g-C 3 N 4 photocatalyst can be ascribed to the combined effects of the nanosheet structure and subsequent efficient separation of photogenerated charge carriers. A tentative mechanism for the photodegradation process was proposed.