# Acid-Free Synthesis of MIL-101/GO Composites with Ultrahigh Selectivity for Adsorptive Separation of C3F8 from N2

## TL;DR

A new eco-friendly method creates a composite material that efficiently captures a harmful gas from industrial waste.

## Contribution

A green acid-free synthesis method for MIL-101/GO composites with record-breaking selectivity for C3F8/N2 separation.

## Key findings

- MIL-101/GO-0.1 achieved a C3F8 adsorption capacity of 210 mg/g in fixed-bed experiments.
- The composite exhibited an IAST separation selectivity of 17,069 for C3F8 over N2.
- Graphene oxide enhances dispersion forces and microporosity, improving C3F8 affinity.

## Abstract

What are the main findings?
A green acid-free route produces MIL-101/GO-0.1, enabling superior C3F8 capture.The content of graphene oxide affects the adsorption properties of the composite material.MIL-101/GO-0.1 achieved a record-breaking IAST separation selectivity of 17,069 for C3F8/N2.

A green acid-free route produces MIL-101/GO-0.1, enabling superior C3F8 capture.

The content of graphene oxide affects the adsorption properties of the composite material.

MIL-101/GO-0.1 achieved a record-breaking IAST separation selectivity of 17,069 for C3F8/N2.

What are the implications of the main findings?
Overcome the current technical bottleneck of low C3F8 adsorption capacity.Green synthesis coupled with high adsorption capacity opens up possibilities for industrial applications.This provides insights for future research into the adsorption and separation of C3F8.

Overcome the current technical bottleneck of low C3F8 adsorption capacity.

Green synthesis coupled with high adsorption capacity opens up possibilities for industrial applications.

This provides insights for future research into the adsorption and separation of C3F8.

As a perfluorinated compound with a high global warming potential, octafluoropropane (C3F8) needs to be efficiently separated from industrial waste gas, but separating it from nitrogen at low concentrations is highly challenging. To address the common drawback of using corrosive acids in conventional MIL-101(Cr) synthesis, this study developed a green, acid-free solvothermal method for preparing graphene oxide (GO)-modified MIL-101(Cr) composites (MIL-101/GO). By systematically varying the GO doping, the optimal composite (MIL-101/GO-0.1) exhibited breakthrough adsorption performance: its equilibrium adsorption capacity for C3F8 reached 210 mg/g in fixed-bed breakthrough experiments. The predicted C3F8 adsorption selectivity relative to N2 reached 17,069, ranking among the highest values reported for adsorbents, indicating a significant performance enhancement over the pristine MIL-101(Cr). Mechanistic analysis reveals that graphene oxide not only increases specific surface area and micropore volume but also enhances dispersion forces, substantially boosting affinity for C3F8. Additionally, the composite exhibits outstanding cycling stability and thermal stability. This study provides a novel eco-friendly synthetic strategy for high-performance metal–organic frameworks and offers a highly promising candidate material for industrial-scale fluorocarbon recovery.