Elucidating the Role of Graphene Oxide Surface Architecture and Properties in Loess Soil Remediation Efficacy

TL;DR

This study explores how graphene oxide's surface properties affect its ability to improve loess soil stability and reduce erosion in the Loess Plateau region.

Contribution

The study reveals the synergistic mechanism of graphene oxide's structure and surface properties in enhancing loess soil water stability.

Findings

A 0.03% addition of graphene oxide significantly reduced loess disintegration.

Highly reduced graphene oxide delayed disintegration due to increased hydrophobicity but lost effectiveness over time.

Adjusting reduction with 50% sodium ascorbate improved soil water-holding capacity in high suction ranges.

Abstract

Loess Plateau is the region with the most concentrated loess distribution and the deepest loess soil layer in the world, and it is facing serious problems of soil erosion and ecological degradation. The nano carbon modification of soil surface properties is a novel strategy for soil improvement and enhancing the soil’s capacity to sequester carbon, which has been extensively researched. However, the mechanisms underlying the influence of carbon surface structure on the efficacy of loess soil remediation remain unclear. Herein, graphene oxide (GO) with a unique two-dimensional structure and adjustable surface properties was optimized as a model carbon filler to investigate the modification effect on loess. As a result, the addition amount of 0.03% GO significantly reduced the disintegration amount of loess, but, if inhibited for a long time, the disintegration effect would weaken. The highly reduced GO can delay the loess disintegration rate due to its enhanced hydrophobicity, but the inhibitory effect fails over a long period of time. After adjusting the reduce degree with a 50% SA (sodium ascorbate), the water-holding capacity of the modified soil in the high suction range is enhanced. This study reveals the synergistic mechanism of the sheet structure and surface properties of GO on the water stability of loess, providing a reference for the prevention and control of soil erosion and ecological restoration in the Loess Plateau.

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