# Multifunctional Halloysite-Glutathione Nanocomposite for Solar CO2 Conversion and Pollutant Sensing

## TL;DR

This paper introduces a sustainable nanocomposite that can convert CO2 into fuel and detect pollutants, using natural materials and green chemistry.

## Contribution

A novel green-synthesized nanocomposite with dual functionality for CO2 conversion and pollutant sensing is developed.

## Key findings

- The nanocomposite achieved 42.2% CO2 conversion with 86.1% CH4 selectivity.
- The material detected bisphenol A with a low limit of detection (0.022 μM) and high sensitivity (5.098 μA μM–1·cm–2).

## Abstract

This study presents
a highly sustainable nanocomposite
platform
for dual applications in both photocatalysis and sensing. The nanomaterial
is synthesized via a green process using natural, readily available
components, including halloysite nanotubes (HNTs), glutathione (GSH),
and xanthopterin, utilizing copper ions (Cu1+) as the catalytically
active species. The synthesis, which exclusively uses green solvents
like tetrahydropyran (THP) and water, involves functionalizing HNTs
with (3-aminopropyl)­triethoxysilane (APTES), followed by the attachment
of GSH as a chelating agent for Cu1+. Finally, xanthopterin
is loaded to act as a light-harvesting antenna. Fourier-transform
infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA)
confirmed the successful functionalization and composition. Scanning
electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis
validated the material’s morphology and elemental composition.
The resulting nanocomposite, HNT-NH2-GSH-Cu1+-X, demonstrated a remarkable synergistic effect, achieving a CO2 conversion of 42.2% and a high (86.1%) CH4 selectivity.
Furthermore, the HNT-GSH-Cu2+ nanocomposite exhibited excellent
electrochemical sensing capabilities for bisphenol A, with a low limit
of detection (LOD) of 0.022 μM and a high sensitivity of 5.098
μA μM–1·cm–2.
The work successfully demonstrates the creation of a sustainable,
multifunctional nanomaterial that addresses critical environmental
challenges by combining efficient solar fuel production with highly
sensitive pollutant detection.