Hierarchical α-MoO3: A versatile eco-friendly material for humidity-assisted ammonia sensing and efficient catalytic activity in wastewater treatment

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2023-11, Vol.676, p.132147, Article 132147
• Main Authors: Kumar, Atul, Rawat, Ravindra Kumar, Chauhan, Pratima
• Format: Article
• Language: English
• Subjects: Co-precipitation; Nanoparticles; NH3 Sensing; Photocatalyst; α-MoO3
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2023.132147

In this work, a facial synthesis of α-MoO3 nanoparticles was done by chemical co-precipitation method. The synthesized α-MoO3 nanomaterials have been reported for sensing and photocatalysis applications together. For sensing, the α-MoO3 was coated on FTO based interdigitated electrodes, and the prepared sensor was tested for numerous concentrations of ammonia (100–600 ppm) under different relative humidity levels (11–33%−56–75% −95% RH). The response and recovery time of α-MoO3 based sensor for 500 ppm of NH3 were 8 s and 11 s under 95% RH, respectively. The prepared α-MoO3 based sensor exhibits high selectivity and stability towards ammonia. To analyze the photocatalytic activity of prepared α-MoO3 nanoparticles, the photodegradation of methylene blue (MB) and methyl orange (MO) under visible light irradiation was studied. The first-order reaction rate constant for MB dye is 0.02434 min−1, and for MO dye is 0.01111 min−1. Finally, the maximum degradation efficiency for MB and MO dyes was calculated to be 95% and 73%, respectively. The given data conclude that the synthesized α-MoO3 nanoparticles can be used as an effective NH3 sensor as well as an efficient photocatalyst in organic dye degradation. [Display omitted] •The chemical co-precipitation technique was used to synthesize the hierarchical α-MoO3 nanoparticles.•The sensor's selectivity, sensitivity, repeatability, and stability towards NH3 were studied.•The relative humidity enhanced the performance of the NH3 sensor.•Fast and efficient removal of methylene blue (95%) and methyl orange (73%) were investigated under visible light irradiations.