High effective catalyst based on Ni doped TiO₂ coated natural cotton fibers for catalytic reduction of organic pollutants

A new type of nickel doped titanium oxide (Ni-TiO2) coated natural cotton fibers (CF) and Ni-TiO2 wrapped sodium alginate (Alg) hydrogel was developed for the efficient reduction of different contaminants. Ni-TiO2 was prepared by low-temperature method and coated on CF using Alg as a binder and entrapped inside Alg hydrogel. Ni-TiO2 coated CF (Ni-TiO2/CF) and Ni-TiO2 wrapped Alg (Ni-TiO2/Alg) were utilized for catalytic elimination of wastewater pollutants. Ni-TiO2/CF and Ni-TiO2/Alg were initially tested as nanocatalysts for reduction of potassium ferricyanide, 4-nitrophenol, congo red, and methylene blue (MB), and exhibited superior catalytic performance toward MB reduction. Different parameters such as catalyst amount, MB concentration, reducing agent amount, and recyclability were optimized. Comparatively, Ni-TiO2/CF revealed the best catalytic performance for MB reduction having the highest reaction rate constant (2.1564 min−1). Ultimately, the catalyst preserved superior activity in recyclability evaluation, confirming that Ni-TiO2/CF is a good catalyst for the efficient removal of MB up to four cycles. Ni-TiO2/CF can more easily be recovered compared to Ni-TiO2/Alg by easily pulling out the fibers from reaction medium, which is the main advantage of Ni-TiO2/CF. Moreover, Ni-TiO2/CF and Ni-TiO2/Alg were examined in real samples, providing the effective reduction of MB. The developed nanocatalyst offers a cost- and time-effective material for environmental safety purpose.