Ultrasonic assisted synthesis with enhanced visible-light photocatalytic activity of NiO/Ag3VO4 nanocomposite and its antibacterial activity

Abstract

The NiO/AgVO nanocomposite photocatalysts were developed by ultrasonic assisted preparation method to study the photocatalytic activity under visible light irradiation. The samples were characterized by UV-DRS, XRD, FT-IR, XPS, SEM, EDX, TEM, EIS and BET analysis. The photocatalytic activity of NiO/AgVO nanocomposite for the photodegradation of 4-Nitro Phenol (4-NP) and Rose Bengal (RB) under visible light irradiation was studied and it is observed that the activity has been much higher than that of the pure AgVO. DRS spectrum shows the absorption edge of NiO-AgVO in visible region of spectrum. The formation of cubic structured NiO and orthorhombic structured AgVO was confirmed by powder X-ray diffraction analysis. The results of XPS analysis confirmed the coexistence of NiO and AgVO in the NiO/AgVO composite. The specific surface area and pore structure of the prepared samples were measured by BET. Enhanced charge separation efficiency was confirmed by electrochemical impedance spectroscopy (EIS) measurements. The kinetics of the NiO/AgVO nanocomposite was proposed to investigate the intervened effects of NiO to AgVO on the promotion of photocatalytic property. NiO/AgVO was found to be stable and reusable without appreciable loss of catalytic activity up to four consecutive cycles. A possible electron-hole transfer mechanism at the NiO/AgVO interface is proposed. It also showed effective and efficient bactericidal activities against Staphylococcus aureus, Streptococcus, Proteus and Escherichia coli bacteria. Our results provide some new insights on the performance of visible light photocatalysts on environmental remediation.

Ag3PO4/NiO Composites with Enhanced Photocatalytic Activity under Visible Light

“… 58 , 59 Thus, the E CB and E VB of Ag 3 PO 4 were 0.31 and 2.6 eV, respectively, while those of NiO were −0.20 and 2.7 eV, respectively, which agrees well with the previous reports. 10 , 14 , 25 , 60 These results are in agreement with those obtained by PL measurement ( Figure 6 ). The composites are of the type-I because the positions of the VB and CB of NiO are lower and higher, respectively, than that of the VB and CB of Ag 3 PO 4 .…”

Advances in ultrasound-assisted synthesis of photocatalysts and sonophotocatalytic processes: A review

“… Enhanced mass transfer: the intense pressure and temperature conditions generated during acoustic cavitation promote the distribution and dispersion of the photocatalyst particles, thereby increasing their contact with the organic pollutants. 37 This improved contact enhances the mass transfer of pollutants to the photocatalyst surface, ultimately accelerating the degradation rate. Thus, in the sonophotocatalysis of bisphenol onto TiO 2 , ultrasonic waves enhanced the dispersion of TiO 2 NPs, leading to increased active sites and facilitating the mass transfer of pollutant molecules.…”

“…Firstly, ultrasound can improve the dispersion of catalyst particles, ensuring a larger surface area available for catalytic reactions. 37 This improved catalyst dispersion promotes better contact between the catalyst and the organic pollutant molecules, facilitating the degradation process. Secondly, ultrasound-induced cavitational activities generate shock waves, creating localized high temperatures and pressures, which can break down complex organic molecules into smaller, more easily degradable fragments.…”

Facile Ultrasound‐Assisted Green Synthesis of NiO/Chitosan Nanocomposite from Mangosteen Peel Extracts as Antibacterial Agents

“…For example, Bhatt et al detailed the manufacture of a NiO/CS nanocomposite beneath ultrasonic radiation; the NiO/CS nanocomposite appears potentially as a dielectric fabric [9]. Ultrasound-assisted methods have also been applied to prepare NiO nanospheres for supercapacitors [27] and NiO/Ag 3 VO 4 nanocomposites for visiblelight photocatalysis and antibacterial applications [28]. Similarly, Raja used a sonochemical route to prepare NiO/ Ag 3 VO 4 ternary nanocomposites with advantages in photodegradation of organic compounds and antibacterial activity compared to conventionally prepared materials [28].…”

“…Ultrasound-assisted methods have also been applied to prepare NiO nanospheres for supercapacitors [27] and NiO/Ag 3 VO 4 nanocomposites for visiblelight photocatalysis and antibacterial applications [28]. Similarly, Raja used a sonochemical route to prepare NiO/ Ag 3 VO 4 ternary nanocomposites with advantages in photodegradation of organic compounds and antibacterial activity compared to conventionally prepared materials [28]. However, to the leading of our information, NiO/CS NPs with antibacterial and antifungal properties have not been prepared by utilizing an ultrasound-assisted coprecipitation method.…”