Surface Recognition Directed Selective Removal of Dyes from Aqueous Solution on Hydrophilic Functionalized Petroleum Coke Sorbents. A Supramolecular Perspective

Abstract

Novel controlled hydrophilic nonporous carbon-based sorbents from petroleum coke were obtained by using a hydrothermal oxidation treatment of shot coke with different H2O2 concentrations. The ability of resulting carbon materials for the selective adsorption of cationic dyes from aqueous solution directed by surface recognition is highlighted for the first time. This approach provides an eco-friendly, low-cost alternative for the preparation of sorbents with unprecedented properties to achieve remarkable selective adsorption independent of the presence of intrinsic porosity. A further advantage of these sorbents is their efficient regeneration capability and reusability without appreciable changes in their adsorption capacity. Results reveal that the dye adsorption capacity is significantly enhanced on multivalent hydrophilic surfaces in comparison to the pristine surface. In addition, a deep insight is offered into the explanation of selective adsorption processes on hydrophilic coke in the function of surface recognition processes based on cooperative multivalent supramolecular interactions such as classical synthons: pyridine–carboxylic acid, O–H···N, cation−π, π–π, and electrostatic interactions. Likewise, this adsorption capacity is highly dependent on the fine-tuning of donor/acceptor binding sites between adsorbate and sorbent. A further type of important supramolecular interaction was observed on the adsorption of dyes onto the hydrophobic coke-raw surface, which is controlled mainly by cation−π and π–π interactions.

Electrospun Adsorptive Nanofibrous Membranes from Ion Exchange Polymers to Snare Textile Dyes from Wastewater

“…This behavior was also described in previous studies where the superior performance of hydrophilic adsorbents for dye removal was attributed to the strong hydrogen bonds between the hydrophilic surface and dye molecules. [37,38] Due to its superior performance, the nanofibrous membrane made from the CEP1 polymer was used in further studies to reveal the adsorption kinetics and mechanism and to test its recyclability. The CEP1 nanofibrous membrane (CEP1-NFM) has a high affinity toward MB and SO, resulting in a high adsorption capacity of 169.1 and 143.9 mg g −1 , respectively, but it exhibited lower adsorption capacities for MR, MO, RH, RB, and CR, in the range of 22.2-70.8 mg g −1 , as shown in Figure 7b.…”

Electrospun Adsorptive Nanofibrous Membranes from Ion Exchange Polymers to Snare Textile Dyes from Wastewater (Adv. Mater. Technol. 10/2021)

“…This behavior was also described in previous studies where the superior performance of hydrophilic adsorbents for dye removal was attributed to the strong hydrogen bonds between the hydrophilic surface and dye molecules. [42,43] Due to its superior performance, the nanofibrous membrane made from the CEP1 polymer was used in further studies to reveal the adsorption kinetics and mechanism and to test its recyclability. The CEP1 nanofibrous membrane (CEP1-NFM) has a high affinity toward MB and SO, resulting in a high adsorption capacity of 169.1 mg g -1 and 143.9 mg g -1 , respectively, but it exhibited lower adsorption capacities for MR, MO, RH, RB, and CR, in the range of 22.2-70.8 mg g -1 , as shown in Figure 7b.…”

Insights into Selective Removal by Dye Adsorption on Hydrophobic vs Multivalent Hydrophilic Functionalized MWCNTs

“…Usually, for this, chemical modifications used strong and hazardous oxidants (e.g., inorganic acids, chlorates, KMnO 3 , etc.). Thus, alternative eco-friendly approaches for the functionalization of carbon materials are of great synthetic significance. ,, …”