# Adsorptive removal of reactive yellow S3R dye from aqueous solutions using green-synthesized copper nanoparticles

## TL;DR

This study explores using copper nanoparticles made from Ficus Benjamina leaves to remove a harmful dye from water.

## Contribution

The novelty is the green synthesis of copper nanoparticles using Ficus Benjamina leaves for efficient dye removal.

## Key findings

- The Langmuir isotherm model best described monolayer adsorption with a maximum capacity of 136.986 mg g−1.
- The pseudo-second-order model confirmed chemisorption as the main mechanism.
- Artificial neural networks and response surface methods validated operational parameters.

## Abstract

Industrial dye pollution poses a significant environmental threat, particularly from azo dyes like Reactive Yellow S3R (RY S3R), which are resistant to conventional treatment methods. This study investigates the efficacy of green-synthesized copper nanoparticles (CuNPs), via Ficus Benjamina leaves, for removing RY S3R from aqueous solutions. The innovative adsorbent Ficus Benjamina nano zero-valent copper (Ficus-nZVCu) was described using SEM, EDAX, and FTIR. Batch adsorption studies assessed the impact of pH, contact time, adsorbent dosage, and starting concentration on elimination efficiency. Several adsorption models were tested, and the Langmuir isotherm (qmax = 136.986 mg g− 1, R2 = 0.9992) revealed the best fit, suggesting monolayer adsorption. Chemisorption was indicated by the pseudo-second-order model (R2 = 0.9993), which was validated by the kinetic analysis. Owing to its redox activity, the green Ficus-nZVCu adsorbent is a promising material for eliminating RYS3R in light of the data acquired and the fruitful research. The impact of major operational parameters was validated using artificial neural network models and response surface methods. According to this study, green-synthesized CuNPs can effectively and safely treat dye-contaminated wastewater.

The online version contains supplementary material available at 10.1038/s41598-025-32372-5.