Fast and efficient degradation of water pollutant dyes and fungicide by novel sulfur-doped graphene oxide-modified Ag3PO4 nanocomposite

Preparation of reed-based hydrothermal carbonized carbon photocatalyst and effective degradation of methylene blue and tetracycline

Hydrothermal carbonation carbon (HTCC) is a promising semiconductor material for the photocatalytic degradation of pollutants. However, the poor charge transfer capability of HTCC and the unclear mechanism of photocatalysis limit its practical application. In this study, a novel Z-type heterojunction photocatalyst of silver carbonate (Ag₂CO₃) and HTCC (Ag₂CO₃/HTCC) was developed for the degradation of methylene blue (MB) and tetracycline (TC) from wastewater using a hydrothermal- coprecipitation method. Compared to Ag₂CO₃ and HTCC, 40% Ag₂CO₃/HTCC had excellent photocatalytic activity and stability. The free radical scavenger experiments showed that •O₂^- and h⁺ were the main substances for the degradation of MB and TC. The intermediates formed during the photodegradation were identified by HPLC-MS, and a possible mechanism and pathway for the degradation of MB and TC by Ag₂CO₃/HTCC was proposed. This study provides a new idea for the synthesis of Z-type HTCC heterojunction with a high-photocatalytic efficiency and its photocatalytic mechanism.

Rational design of Ag2CO3-loaded SGO heterostructure with enhanced photocatalytic abatement of organic pollutants under visible light irradiation

The photocatalytic activity of semiconducting silver carbonate was restricted by the lower stability and fast recombination rate of photogenerated electron-hole pairs. Sulfur-doped graphene oxide (SGO) is used as a cocatalyst for improving the photocatalytic activity of Ag₂CO₃ by reducing the recombination rate. A simple precipitation method was used for the modification of silver carbonate. The chemical, physical, optical, and electrochemical properties of the modified photocatalyst was characterized by XRD, SEM, TEM, UV-vis DRS, XPS, CV, impedance, and amperometry. The fabricated SGO-Ag₂CO₃ composite was successfully degraded various organic pollutants such as methylene blue (MB), rhodamine B(RhB), methyl orange (MO), tartrazine, and thiram with augmented mineralization. The optimization of weight percentage of the developed binary composite with 0.5% SGO-Ag₂CO₃ showed enhanced photocatalytic degradation and followed pseudo-first-order kinetics with rate constant 0.126. More than 90% of degradation efficiency of the pollutants within a short time promises the binary heterostructure for future industrial applications. The excellent stability and reproducibility of the composite opened a new route in the treatment of wastewater.