Clays enhanced with niobium: potential in wastewater treatment and reuse as pigment with antibacterial activity

• Silvia Jaerger,
• Patricia Appelt,
• Mario Antônio Alves da Cunha,
• Fabián Ccahuana Ayma,
• Ricardo Schneider,
• Carla Bittencourt and
• Fauze Jacó Anaissi

Beilstein J. Nanotechnol. 2025, 16, 141–154, doi:10.3762/bjnano.16.13

• photocatalysts for treating solutions containing the MB dye (400 mg·L−1) at 25 °C. The results showed adsorption and photocatalysis efficiency above 94% for both samples. The blue-colored BEOx and BEPh samples were then applied as a hybrid pigment. The power pigment and its dispersion in colorless paint were

• evaluated by the CIEL*a*b* color space, and the ΔE parameters show values above 12, indicating a very strong color parameter difference. Subsequently, the efficacy of BEOx and BEPh as a hybrid pigment was assessed using the minimum inhibitory concentration (MIC) assay against two bacteria strains: Bacillus

• cereus (ATCC 10876) and Proteus mirabilis (ATCC 35649). The analysis revealed remarkable antibacterial activity against Proteus mirabilis, suggesting a preferential selectivity for Gram-negative bacteria. Keywords: adsorption; bentonite; hybrid pigment; niobium; photocatalysis; water remediation