Morphology-Controlled Synthesis of BiVO₄ Materials and Their Ethanol Gas Sensing Properties

Abstract

BiVO 4 porous microspheres were fabricated by a facile hydrothermal reaction. Various analytical techniques such as x-ray diffraction, scanning electron microscope, x-ray photoelectron spectroscopy, and N 2 adsorption-desorption were adopted to characterize their structure, morphology, and chemical composition. The results showed the molecular weight of PEG had a significant influence on the morphologies of BiVO 4 samples, and high molecular weight of PEG favored the formation of porous sphere-shaped nanostructure due to longer chain-like coordination complexes. The gas sensing properties of these BiVO 4 microspheres were further investigated, and all the four BiVO 4 sensors demonstrated the increasing responses with the increase of working temperatures, and reached their maximum values at 340 • C. The ethanol-selective characteristics of the BiVO 4 sensor synthesized by the assist of PEG1000 towards 200 ppm ethanol presented significantly higher gas response than all the other interfering gases. Moreover, the BiVO 4 sensor also displayed fast response/recovery, and excellent stability for 14-day continuous measurement. INDEX TERMS Monitoring, BiVO 4 , ethanol, gas sensor.

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“…To pursue superior gas-sensitive properties, researchers are keen on realizing a controllable synthesis of materials with oriented or tailored structures. Taking hydrothermal reaction, which is an eco-friendly and time- and cost-effective method suitable for mass production, for example, a surfactant additive is regarded to be more efficient to intensify the crystal anisotropy and facilitate its directional growth compared with hydrothermal temperature and time. , In this process, surfactants commonly serve as capping agents. , Anionic sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), cationic cetyltrimethyl ammonium bromide (CTAB), nonionic PEG, polyvinylpyrrolidone (PVP), or their complexes are most frequently used.…”

“…28,29 In this process, surfactants commonly serve as capping agents. 30,31 Anionic sodium dodecyl sulfate (SDS), 32 sodium dodecyl benzene sulfonate (SDBS), 33 cationic cetyltrimethyl ammonium bromide (CTAB), 34 nonionic PEG, 35 polyvinylpyrrolidone (PVP), 36 or their complexes 28 are most frequently used.…”