Fabrication of porous g-C 3 N 4 and supported porous g-C 3 N 4 by a simple precursor pretreatment strategy and their efficient visible-light photocatalytic activity

Micron-Scale Vertical MoS2/Porous g-C3N4 Piezocatalyst via a Precursor's Supramolecular Self-Template Architecture: Degradation and Hydrogen Evolution

Piezocatalysis can effectively harvest various kinds of mechanical energy with high entropy from the environment and drive some redox reactions without light irradiation, where MoS2- and g-C3N4-based piezocatalysts are recent research hotspots. This study constructs an architecture of ordered melamine hydrochloride-cyanuric acid/MoO42- supramolecular precursor via self-assembly, serving as a self-template for in situ tight growth of vertically aligned micron-scale MoS2 on porous foam-like g-C3N4(CMx) under S vapor with a bioinspired rooting and sprouting-like process. Experiments, DFT calculations, and finite element simulations collectively confirm the high piezoresponse of the CMx with high exposure of active sites and enhanced mechanical energy collection. The vertical interfaces and built-in electric fields in the composite induce efficient charge carrier separation and transfer. The optimized CM0.77 efficiently degrades various organic dyes and antibiotic under dark ultrasound [rhodamine B (RhB): 0.47 s-1, methyl orange (MO): 0.05 s-1, methylene blue (MB): 0.21 s-1, and tetracycline hydrochloride (TC): 0.03 s-1] and achieves hydrogen evolution (2431 μmol·g-1·h-1). Under simulated water flow (10 L/min), the expanded CM0.77/Al2O3 porous foam ceramic (CM/alumina ceramic) purifier device degrades 95% of 400 mL of RhB within 25 min. The developed ordered vertical MoS2/g-C3N4 piezocatalyst demonstrates rapid pollutant degradation and efficient hydrogen evolution under water flow and ultrasound, providing new insights for constructing multidimensional piezoelectric composites for environmental remediation and clean energy production.

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

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.

Synergism of ultrafine RuCo alloy nanoparticles on graphite carbon nitride for an efficient ammonia borane hydrolysis

Synergism of ultrafine RuCo alloy nanoparticles on graphite carbon nitride were achieved for an efficient ammonia borane hydrolysis.

g-C3N4/γ-Fe2O3/TiO2/Pd: a new magnetically separable photocatalyst for visible-light-driven fluoride-free Hiyama and Suzuki–Miyaura cross-coupling reactions at room temperature

g-C₃N₄/γ-Fe₂O₃/TiO₂/Pd is developed as a new magnetically separable photocatalyst for efficient fluoride-free Hiyama and Suzuki–Miyaura cross-coupling reactions at room temperature under visible light irradiation.

Photocatalytic Hydrogen Production: Role of Sacrificial Reagents on the Activity of Oxide, Carbon, and Sulfide Catalysts

Photocatalytic water splitting is a sustainable technology for the production of clean fuel in terms of hydrogen (H2). In the present study, hydrogen (H2) production efficiency of three promising photocatalysts (titania (TiO2-P25), graphitic carbon nitride (g-C3N4), and cadmium sulfide (CdS)) was evaluated in detail using various sacrificial agents. The effect of most commonly used sacrificial agents in the recent years, such as methanol, ethanol, isopropanol, ethylene glycol, glycerol, lactic acid, glucose, sodium sulfide, sodium sulfite, sodium sulfide/sodium sulfite mixture, and triethanolamine, were evaluated on TiO2-P25, g-C3N4, and CdS. H2 production experiments were carried out under simulated solar light irradiation in an immersion type photo-reactor. All the experiments were performed without any noble metal co-catalyst. Moreover, photolysis experiments were executed to study the H2 generation in the absence of a catalyst. The results were discussed specifically in terms of chemical reactions, pH of the reaction medium, hydroxyl groups, alpha hydrogen, and carbon chain length of sacrificial agents. The results revealed that glucose and glycerol are the most suitable sacrificial agents for an oxide photocatalyst. Triethanolamine is the ideal sacrificial agent for carbon and sulfide photocatalyst. A remarkable amount of H2 was produced from the photolysis of sodium sulfide and sodium sulfide/sodium sulfite mixture without any photocatalyst. The findings of this study would be highly beneficial for the selection of sacrificial agents for a particular photocatalyst.