On the Interactions and Synergism between Phases of Carbon⁻Phosphorus⁻Titanium Composites Synthetized from Cellulose for the Removal of the Orange-G Dye

• Published in: Materials Vol. 11; no. 9; p. 1766
• Main Authors: Hamad, Hesham, Castelo-Quibén, Jesica, Morales-Torres, Sergio, Carrasco-Marín, Francisco, Pérez-Cadenas, Agustín F, Maldonado-Hódar, Francisco J
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.09.2018; MDPI
• Subjects: Acids; Activated carbon; Adsorption; Carbon; Carbonization; Cellulose; chemical functionalization; Composite materials; Crystalline cellulose; Dyes; Freshwater resources; Impregnation; Indoor air quality; microcrystalline cellulose; Morphology; Nanocomposites; Orange G; Outdoor air quality; Oxidation; Particle size; Phosphates; Phosphoric acid; Phosphorus; Photocatalysis; Photodegradation; physicochemical properties; Pollutants; Polyphosphates; Porosity; Precursors; Scanning electron microscopy; Semiconductors; Spectrum analysis; synergism; Titanium; Titanium dioxide; VOCs; Volatile organic compounds; United Kingdom > UK; Germany; Spain; Orange G; chemical functionalization; physicochemical properties; polyphosphates; microcrystalline cellulose; synergism; photocatalysis
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma11091766

Carbon⁻phosphorus⁻titanium composites (CPT) were synthesized by Ti-impregnation and carbonization of cellulose. Microcrystalline cellulose used as carbon precursor was initially dissolved by phosphoric acid (H₃PO₄) to favor the Ti-dispersion and the simultaneous functionalization of the cellulose chains with phosphorus-containing groups, namely phosphates and polyphosphates. These groups interacted with the Ti-precursor during impregnation and determined the interface transformations during carbonization as a function of the Ti-content and carbonization temperature. Amorphous composites with high surface area and mesoporosity were obtained at low Ti-content (Ti:cellulose ratio = 1) and carbonization temperature (500 °C), while in composites with Ti:cellulose ratio = 12 and 800 °C, Ti-particles reacted with the cellulose groups leading to different Ti-crystalline polyphosphates and a marked loss of the porosity. The efficiency of composites in the removal of the Orange G dye in solution by adsorption and photocatalysis was discussed based on their physicochemical properties. These materials were more active than the benchmark TiO₂ material (Degussa P25), showing a clear synergism between phases.