Defects were formed in a BaSO4catalyst by controlling its synthesis and it offered excellent activity for the dehydration of lactic acid to acrylic acid.

Chemiresistive gas sensors with low power consumption, high sensitivity, and selectivity are of great significance for low-cost and efficient real-time gas detection. Herein, we present a highly sensitive and selective H 2 S gas sensor employing thin-layer graphene oxide (GO)-loaded sub-4 nm diameter SnO 2 quantum wires (QWs) through a simple mechanical mixing process. The SnO 2 QWs with the diameter smaller than 4 nm are decorated uniformly on the surface of the GO, which endows the heterostructure with high charge transport efficiency. The surface activity and adsorbed oxygen species of SnO 2 QWs, and the fast charge transfer channel of the GO nanosheet, are confirmed vital to the enhanced gas-sensing properties. As demonstrated, the asfabricated sensors exhibit an optimum gas-sensing performance for ppb-level H 2 S detection at 70 °C. In addition, our sensors are selectively sensitive to H 2 S and even show fast dynamic response and recovery kinetics toward ppb-level H 2 S at the high relative humidity of 85%. Moreover, GO-loaded SnO 2 QWs with solution processability enable the demonstration of a paper-based flexible H 2 S sensor for 500 ppb H 2 S detection with long-term stability. This result helps us to understand that the design and synthesis of 1D SnO 2 QWs/2D GO nanosheet nanocomposites will provide new paradigms for the future development of H 2 S-sensitive and selective materials.

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Hierarchical graphene oxide/molybdenum sulphide/carbon nitride (GO/MoS2/g‐C3N4) ternary nanostructure with visible‐light‐driven photocatalytic property are prepared employing a simple and facile solvothermal method. Systematical characterizations like transmission electron microscopy (TEM), X‐ray diffraction (XRD), Fourier transform infrared spectra (FTIR), UV‐vis diffuse reflectance spectra (DRS), and photoluminescence spectra, have been carried out to figure out composition, structure and optical properties of the ternary composites, accompanied with their physical and chemical interface state among GO, MoS2 and g‐C3N4. The GO/MoS2/g‐C3N4 ternary photocatalyst exhibits excellent visible‐light‐induced photocatalytic activity for Rhodamine B (RhB) degradation reaching up to 96.7%. More significantly, the hierarchical nanostructured ternary system shows good photostability and reusability with a minor degradation of 1.5%. The enhanced visible‐light photodegradation properties would be owing to the synergetic effects of GO, MoS2 and g‐C3N4 in the hierarchical ternary GO/MoS2/g‐C3N4 nanocomposites favourable for the photogenerated electrons‐holes separation and transfer. In addition, the surface reaction species is also confirmed by the trapping experiments and a reaction mechanism is proposed.