Uniform-size RuAu bimetallic nanoalloy anode for photoelectrochemical remediation of diclofenac sodium

• RuAu bimetallic nanoalloys are synthesized by facile one-pot protocol. • FTO/RuAuBNAs photoanode was constructed for PEC applications. • The PEC system achieved higher diclofenac removal efficiency of 95 %. • The holes appeared as the major contributing species in PEC process. • The photoanode exhibited remarkable stability and reusability. Bimetallic nanocatalysts are widely utilized for the photoelectrochemical degradation of persistent pharmaceutical contaminants. However, fabricating monodisperse nanocatalysts is crucial to achieving consistency and high efficiency in their applications. Thus, highly uniform and monodisperse powdered ruthenium-gold bimetallic nanoalloys (RuAuBNAs) from an aqueous solution were prepared from a facile one-pot route for the photoelectrochemical (PEC) degradation of diclofenac sodium (DFC). The physicochemical and structural properties were investigated using TEM, XRD, SAXS, EDS, TGA, UV–vis, and FTIR spectroscopy. The TEM and SAXS analysis showed that the obtained nanoalloys were highly monodisperse, mainly of uniform size and shape with a mean particle size of 9.49 ± 0.06 nm. The PEC performance showed a better degradation rate (0.0148 min −1 ) which is 3.89 and 5.92 folds higher than those of photocatalysis (PC) and electrocatalysis (EC) under the bias potential of 1.5 V, respectively. The PEC reached a total organic carbon (TOC) removal of 71 % while the FTO/RuAuBNAs anode displayed appreciable stability after four reuse cycles. The improvement in PEC performance was linked to the synergistic effect of photocatalysis and electrocatalysis. This study offers a refresher foundation for using bimetallic nanoalloys to construct efficient PEC systems for the abatement of organic pollutants.