TiO₂/g-C₃N₄/SO₃H(IL): Unique Usage of Ionic Liquid-Based Sulfonic Acid as an Efficient Photocatalyst for Visible-Light-Driven Preparation of 5-HMF from Cellulose and Glucose

Abstract

Upgrading of biomass wastes to value-added materials has been incessantly pursued worldwide with diverse applications, especially deploying photocatalytic composites encompassing metal oxides with acidic and carbon compounds. Herein, the fabrication of a morphologically unique acidic catalyst encompassing a two-dimensional (2D) TiO2/g-C3N4 heterojunction feature is described for the generation of 5-hydroxymethylfurfural (5-HMF), which exploits the acidic/ionic liquid (IL) bifunctional photocatalysis under visible light. The structural integrity of the synthesized TiO2/g-C3N4/SO3H­(IL) was corroborated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy–energy-dispersive spectroscopy (EDX–EDS), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), UV–vis, Tauc plots, transmission electron microscopy (TEM), and Brunauer–Emmett–Teller–Barrett–Joyner–Halenda (BET–BJH) analyses. Keeping environmental impact in mind, there are compelling advantages in the development of bio-derived pathways to access ILs from natural renewable resources. The outcomes of environmental assessments have revealed that the incorporation of TiO2 in g-C3N4 and ClSO3H can reduce the probability of recombination due to ionic charges present, therefore enhancing the photocatalytic activity via the transformation of cellulose and glucose to produce 5-HMF in higher yields, with the optimum conditions being reaction in water under a blue light-emitting diode (LED), at 100 °C, for 1–1.5 h. The main advantages of this production method include minimum number of synthetic steps as well as ample availability of and easy access to primary ingredients. While a significant volume of 5-HMF was produced under blue light-emitting diode (LED) radiation, the selectivity was drastically reduced in the dark. The salient attributes of the catalyst comprise stability in air, robustness, reusability, and its overall superior activity that is devoid of hazardous additives or agents. This inimitable method has uncovered a newer strategy for enhancing the photocatalytic attributes of deployed semiconducting materials for numerous photocatalytic functions while adhering to the tenets of environmental friendliness.

Energy-efficient and eco-friendly continuous production of 5-CMF in a UV-ultrasound irradiated catalytic packed bed reactor: heterogeneous kinetics, reactor simulation and LCA analysis

“…However, no work has been reported on the 5-CMF production employing a heterogeneous solid catalyst alone to date, even though various types of heterogeneous solid catalysts, including zeolites, sulfonated carbon-based materials, photocatalysts, metal oxides, and acidic ion exchange resins, have been employed for the production of 5-HMF. [8][9][10] Recently, some works on the photocatalytic chlorination of organic substances and photoactivation of organic chlorides have been reported. 11 For instance, Ma et al 12 successfully produced methyl chloride using an alkyl chloride salt as the chlorine source under the copper-doped TiO 2 photocatalytic system.…”

Production of 5-Hydroxymethyl-2-furan Carboxylic Acid Using Biobased Silver Nanoparticles in Deep Eutectic Substrate Reaction Mixtures

“…In this context, attention to the stability of chemical processes is necessary and researchers are currently focusing on this issue. − In particular, an effective strategy to cope with the reduction of fossil energy resources is the use of renewable raw materials such as biomass. − Indeed, the conversion of biomass into key building blocks or fine chemicals can allow for a partial replacement of fossil resources, and this field has become a major focus for both academia and industry. Among the platform molecules derived from lignocellulosic biomass, 5-hydroxymethylfurfural (5-HMF) is considered an important molecule with applications in biobased polymer chemistry. − Different chemical modifications of 5-HMF permit acquiring added-value chemicals: 2,5-bis­(hydroxymethylfuran) (BHMF) by reduction, 2,5-dimethylfuran (DMF) by hydrodehydroxylation, or 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), 2,5-diformylfuran (DFF), 5-formyl-2-furancarboxylic acid (FFCA) by partially oxidation and 2,5-furandicarboxylic acid (FDCA) by per-oxidation (Scheme ). − Among these chemicals, HMFCA is a very relevant substrate − that plays a role in the production of furanic polyesters, and on the other hand, it has potent antitumor activity. − However, the selective conversion of 5-HMF to HMFCA is generally challenging, as only the oxidation of the formyl group to the corresponding carboxylic group has to be performed.…”

Mechanical, magnetic and electronic properties of 2D MSX (M = Ti, V, Co and Ni, X = Br and I)

“…1 Their unique properties hold huge promise for a variety of applications, encompassing fields such as microelectronics, 2,3 sustainable energy technologies, 4,5 and biomedicine. 6,7 Recently, 2D metal oxyhalides and sulfide halides have attracted considerable attention, which stems from their tunable magnetic and electronic properties, [8][9][10] facile fabrication processes, 11,12 and versatile applicability across a diverse range of research areas. 13,14 Their diverse properties are highly related to the interlayer coupling and dimensional effects.…”