LignoPhot: Conversion of hydrolysis lignin into the photoactive hybrid lignin/Bi4O5Br2/BiOBr composite for simultaneous dyes oxidation and Co2+ and Ni2+ recycling

• Published in: Chemosphere (Oxford) 2021-09, Vol.279, p.130538-130538, Article 130538
• Main Authors: Budnyak, Tetyana M., Onwumere, Joy, Pylypchuk, Ievgen V., Jaworski, Aleksander, Chen, Jianhong, Rokicińska, Anna, Lindström, Mikael E., Kuśtrowski, Piotr, Sevastyanova, Olena, Slabon, Adam
• Format: Article
• Language: English
• Subjects: Adsorption; Bioinorganic interfaces; Hydrolysis lignin; Photocatalysis; Water treatment
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2021.130538

Valorization of lignin is still an open question and lignin has therefore remained an underutilized biomaterial. This situation is even more pronounced for hydrolysis lignin, which is characterized by a highly condensed and excessively cross-linked structure. We demonstrate the synthesis of photoactive lignin/Bi4O5Br2/BiOBr bio-inorganic composites consisting of a lignin substrate that is coated by semiconducting nanosheets. The XPS analysis reveals that growing these nanosheets on lignin instead on cellulose prevents the formation of Bi5+ ions at the surface region, yielding thus a modified heterojunction Bi4O5Br2/BiOBr. The material contains 18.9% of Bi4O5Br2/BiOBr and is effective for the photocatalytic degradation of cationic methylene blue (MB) and zwitterionic rhodamine B (RhB) dyes under light irradiation. Lignin/Bi4O5Br2/BiOBr decreases the dye concentration from 80 mg L−1 to 12.3 mg L−1 for RhB (85%) and from 80 mg L−1 to 4.4 mg L−1 for MB (95%). Complementary to the dye degradation, the lignin as a main component of the composite, was found to be efficient and rapid biosorbent for nickel, lead, and cobalt ions. The low cost, stability and ability to simultaneously photo-oxidize organic dyes and adsorb metal ions, make the photoactive lignin/Bi4O5Br2/BiOBr composite a prospective material for textile wastewaters remediation and metal ions recycling. [Display omitted] •Raw hydrolysis lignin material was functionalized with a semiconductor photocatalyst.•A controlled growth of Bi4O5Br2/BiOBr nanostructures on lignin surface was achieved.•The chosen conditions of synthesis led to save the functionality of the biopolymer.•The LignoPhot is efficient for simultaneous dyes degradation and metals recycling.