Ag/AgCl-NW/rGO composite for high-efficiency visible-light-driven photocatalytic activity of rhodamine B

Abstract

One of the biggest environmental challenges still facing wastewater treatment is the efficient breakdown of dye pollutants such as rhodamine B (RhB). The development of effective photocatalysts that function in sunlight and visible light can greatly improve wastewater treatment systems. Combining reduced graphene oxide (rGO) with silver/silver chloride core–shell nanowires (Ag/AgCl-NW) might offer special optical and structural properties that enhance its photocatalytic activity for RhB degradation. Ag/AgCl-NW/rGO composite was produced by electroplating rGO onto stainless steel and then covering it with evenly dispersed Ag/AgCl-NW. In 120 min, the Ag/AgCl-NW/rGO composite degraded 99.78% of RhB (dye concentration of 10 ppm at pH 8) under visible light, following pseudo-first-order kinetics (rate constant: 0.0498 min⁻¹) and maintaining its effectiveness for four reuse cycles. The photodegradation pathway is primarily dominated by direct chromophore degradation rather than the more typical de-ethylated rhodamine (Rh-110) pathway. Unlike RhB, Rh-110 is only produced when exposed to visible light, and it is completely oxidized in the presence of sunlight. These findings show the Ag/AgCl-NW/rGO composite to be a promising photocatalyst for effective RhB degradation in visible light and enhanced efficiency in sunlight, highlighting its potential for sustainable wastewater treatment applications.