Reduced graphene oxide composites and its real-life application potential for in-situ crude oil removal
Graphical abstract
Introduction
In recent years, frequent oil spill has exerted great threat to the environment, especially the sea and coastal places, therefore has become a worldwide environmental issue (Peterson et al., 2003; Jernelov, 2010; Brette et al., 2014). Conventional cleanup approaches, such as oil skimmer (Broje and Keller, 2006), bioremediation (Macnaughton et al., 1999), and in-situ burning (Beyer et al., 2016) have been widely used to remove the oil contamination. But most of these approaches were either labor-intensive or time-consuming. The negative impact on the air quality due to in-situ burning made it not desirable for future oil pollution treatment. Since most of the oil density is lower than water, floating absorbents offered an alternative cleanup approach by in-situ oil absorption (Adebajo et al., 2003). Typical naturally-occurring absorbents (such as straw, zeolites, and wool fibers) (Liu et al., 2015) and common synthetic absorbents (such as polyurethane and polyethylene) (Ke et al., 2014; Ali et al., 2018, 2019a) were used for this purpose. However, these absorbents usually suffer from lack of reusability or low absorption efficiency (Gupta et al., 2017; Ali et al., 2019b; Nodeh et al., 2016).
Recently, novel adsorbing materials with improved performance have been reported (Wang et al., 2015a; Zhang et al., 2013; Hayase et al., 2013; Mu et al., 2015; Yu et al., 2015; Ferrero et al., 2019; Basheer, 2018). Through silylation modification, a hydrophilic sponge could be turned into a hydrophobic absorbent for oil-water separation (Zhang et al., 2013). A superhydrophobic and superoleophilic “sponge-like” aerogel could be obtained via sol–gel reaction, in which methyltriethoxysilane (MTES) and dimethyldiethoxysilane (DMDES) were used as co-precursors (Yu et al., 2015). Functional nanoparticles integrated into material matrix (such as polymers) could provide additional surface roughness and increased hydrophobicity for oil absorption (Gupta et al., 2017). But most of these methods were not applicable for crude oil absorption due to its high viscosity (100–10000 mPa s at room temperature) (Chang et al., 2018; Zhang et al., 2018; Ge et al., 2017). Therefore, besides hydrophobicity/oleophilicity, the key for crude oil absorption is to decrease oil viscosity for better fluidity (Yang et al., 2018). In this regard, Ge et al. recently demonstrated a Joule-heated graphene-wrapped sponge that was able to convert electricity into thermal energy to reduce the crude oil viscosity (Ge et al., 2017). However, since the electro-thermal conversion would require additional electric power input, materials with photothermal properties might be a better candidate for in-field applications. In fact, photothermal materials with the ability to convert light to heat efficiently have been used in desalination, clean water production, catalysis and cancer therapy (Jain et al., 2008; Liu et al., 2013; Zhang et al., 2015, 2017a; Xu et al., 2017; Wang, 2018; Jiang et al., 2018). Recently, photothermal oil absorbents were fabricated through coating photothermal materials (such as polydopamine and polypyrrole) on the sponge (Chang et al., 2018; Zhang et al., 2018; Wu et al., 2018). However, the time-consuming preparation process and instability of polymers in heat continued to be a challenge (Wang et al., 2019). Although graphene could be a suitable substitution due to its heat stability, hydrophobic/oleophilic characteristic and photothermal property, its high hydrophobicity could pose difficulty in applying in aqueous environment (Yang et al., 2010, 2013; Hu et al., 2017; Chung et al., 2013; Robinson et al., 2011; Fojtu et al., 2017).
Against this background, this study set out to explore the use of graphene-based photothermal nanomaterials in combination with floating matrix to achieve in situ crude oil absorption. A facile one-step hydrothermal synthesis method was used to achieve graphene oxide (GO) to reduced graphene oxide (RGO) conversion and loading to melamine sponge (MS) simultaneously. The resulted RGO-MS composite possesses desirable hydrophobicity and oleophilicity. Upon light irradiation, the photothermal property of RGO enabled fast temperature rise thus lowered the crude oil viscosity. Moreover, by designing and fabricating a mounting platform through 3D-printing, multiple RGO-MS composites could be applied, retrieved, and replaced after usage. The reusability of such composite was also evaluated.
Section snippets
Fabrication and characterization of RGO-MS composites
The commercially available MS was selected as the substrate material due to its characteristics, including low cost, low density (<10 mg/cm3), high porosity (>99%), high compressibility, and thermal stability (Gao et al., 2018; Zhang et al., 2017b; Stolz et al., 2016). The schematic illustration of the fabrication process of RGO-MS composites is shown in Fig. S1. The ammonia solution played an important role of promoting the stability of GO suspension through electrostatic repulsion and l
Conclusion
In conclusion, the RGO-MS composite fabricated by simultaneously reducing GO to RGO and loading to melamine sponge has excellent hydrophilicity/oleophilicity and photothermal property that enabled effective crude oil absorption. Upon light irradiation, the RGO-MS composite achieved in-situ crude oil absorption 95 times of its own weight within 12 min. And 3D-printed mounting platform provided easy retrieval of the composites for reuse purpose. Our study has demonstrated a facile synthesis
Materials
Graphene oxide (GO, >99%, leaf size of 0.5–3 μm, thickness of 0.55–1.2 nm) was purchased from Aladdin Bio-Chem Co. Ltd. (Shanghai, China). l-Ascorbic acid (L-AA) was obtained from Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China). ammonia solution (28.0–30.0%) was produced by InnoChem Science & Technology Co. Ltd. (Beijing, China). The crude oil and diesel were both obtained from China National Petroleum Corporation. Other light oils and organic solvents, including castor oil, soybean oil,
CRediT authorship contribution statement
Xiaoxiao Wang: Data curation, Formal analysis, Writing - original draft. Guotao Peng: Formal analysis. Mengmeng Chen: Visualization. Mei Zhao: Data curation. Yuan He: Data curation, Formal analysis. Yue Jiang: Data curation. Xiaozhen Zhang: Data curation. Yao Qin: Conceptualization. Sijie Lin: Conceptualization, Writing - review & editing.
Declaration of competing interest
The authors declare no conflict of interest.
Acknowledgements
This work was financially supported by the National Key R&D Program of China (Grant No. 2018YFC1803100), National Science Foundation of China (Grant No. 21777116) and the Fundamental Research Funds for the Central Universities.
References (53)
- et al.
Graphene based adsorbents for remediation of noxious pollutants from wastewater
Environ. Int.
(2019) New generation nano-adsorbents for the removal of emerging contaminants in water
J. Mol. Liq.
(2018)- et al.
Environmental effects of the Deepwater Horizon oil spill: a review
Mar. Pollut. Bull.
(2016) - et al.
A two-step hydrophobic fabrication of melamine sponge for oil absorption and oil/water separation
Surf. Coating. Technol.
(2018) - et al.
Ternary silicone sponge with enhanced mechanical properties for oil-water separation
Polym. Chem.
(2015) - et al.
Determination of free melamine content in melamine-formaldehyde resins by Raman-spectroscopy
Vib. Spectrosc.
(1995) - et al.
Ultrasonic-microwave assisted synthesis of stable reduced graphene oxide modified melamine foam with superhydrophobicity and high oil adsorption capacities
Chem. Eng. J.
(2016) - et al.
Melamine-derived carbon sponges for oil-water separation
Carbon
(2016) - et al.
Easy and green synthesis of reduced graphite oxide-based hydrogels
Carbon
(2011) - et al.
Solar-heated graphene sponge for high-efficiency clean-up of viscous crude oil spill
J. Clean. Prod.
(2019)
Chemical analysis of graphene oxide films after heat and chemical treatments by X-ray photoelectron and Micro-Raman spectroscopy
Carbon
Porous materials for oil spill cleanup: a review of synthesis and absorbing properties
J. Porous Mater.
Water treatment by new-generation graphene materials: hope for bright future
Environ. Sci. Pollut. Control Ser.
Removal of Copper(II) and Zinc(II) ions in water on a newly synthesized polyhydroquinone/graphene nanocomposite material: kinetics, thermodynamics and mechanism
Chemistryselect
Crude oil impairs cardiac excitation-contraction coupling in fish
Science
Improved mechanical oil spill recovery using an optimized geometry for the skimmer surface
Environ. Sci. Technol.
Solar-assisted fast cleanup of heavy oil spills using a photothermal sponge
J. Mater. Chem.
Specific nanotoxicity of graphene oxide during zebrafish embryogenesis
Nanotoxicology
Biomedical applications of graphene and graphene oxide
Acc. Chem. Res.
Vitamin C is an ideal substitute for hydrazine in the reduction of graphene oxide suspensions
J. Phys. Chem. C
Reduced graphene oxide-coated microfibers for oil-water separation
Environ. Sci.: Nano
Environmental impact and potential health risks of 2D nanomaterials
Environ. Sci.: Nano
Joule-heated graphene-wrapped sponge enables fast clean-up of viscous crude-oil spill
Nat. Nanotechnol.
Oil/water separation techniques: a review of recent progresses and future directions
J. Mater. Chem.
Facile synthesis of marshmallow-like macroporous gels useable under harsh conditions for the separation of oil and water
Angew. Chem. Int. Ed.
Tailoring graphene oxide-based aerogels for efficient solar steam generation under one sun
Adv. Mater.
Cited by (27)
Advances in special wettable materials for adsorption separation of high-viscosity crude oil/water mixtures
2023, Chemical CommunicationsMultifunctional superhydrophobic copper mesh for efficient oil/water separation and fog collection
2023, Colloids and Surfaces A: Physicochemical and Engineering AspectsAdsorption-enhanced processes for the treatment of oily wastewater
2023, Advanced Technologies in Wastewater Treatment: Oily WastewatersPreparation of Janus nanosheets composed of gold/palladium nanoparticles and reduced graphene oxide for highly efficient emulsion catalysis
2022, Journal of Colloid and Interface ScienceCitation Excerpt :The contact angle on bottom side was 57° (Fig. 4c), confirming its hydrophilicity, while the contact angle on top side was 100° (Fig. 4c), confirming its hydrophobicity. The hydrophobic nature may possibly arise from the hydrophobicity of the rGO surface, which has been confirmed by many reports [24–29]. The hydrophilic nature may arise from the hydrophilicity of the coated AuNPs, which possess high surface energy and are usually hydrophilic [30–33].
Graphene-based macromolecular assemblies as high-performance absorbents for oil and chemical spills response and cleanup
2022, Journal of Environmental Chemical Engineering