One-step microwave-assisted hydrothermal synthesis of α-Bi2Mo3O12 without surfactants at low temperature for their application in tetracycline photodegradation

Abstract

This research reports obtaining the bismuth molybdate phase α-Bi 2 Mo 3 O 12 by a microwave-assisted hydrothermal method using sustainable environmental conditions compared to the typical material synthesis by solid-state reaction. The α-Bi 2 Mo 3 O 12 sample obtained by microwave assistance (BMO) was evaluated for the photocatalytic degradation of tetracycline (TC) using simulated sunlight and compared against the same phase obtained by the typical solid-state reaction (BSS). BMO presented a higher TC degradation efficiency (56%) than BSS (35%). This was attributed to greater surface area and lower electron-hole pair recombination according to the photoluminescence spectrum than BSS. The scavenger tests determined that H 2 O 2 is the main specie involved in the TC degradation, which was corroborated by the construction of the bands position diagram carried out by X-ray Photoelectron Spectroscopy (XPS) determination. The conduction band of BMO was calculated at -1.62 eV, which allows it to generate H 2 O 2 at a potential of 0.70 V. • The BMO sample presented a higher surface area than the BSS sample • The VB and CB positions were calculated to be +1.28 eV and -1.62 eV by XPS analysis • The BMO sample showed the higher photocatalytic efficiency in the TC degradation • The scavengers test determined that H 2 O 2 is the main species of TC degradation • The α-Bi 2 Mo 3 O 12 presented high stability and caused a partial mineralization of TC