Preparation and Application of Sodium-Lanthanum Molybdate for the Photocatalytic Degradation of Coomassie Brilliant Blue G-250 Dye

Caique D A Lima; Joyce A Borges; Italo A L Santos; Angel A Hidalgo; Josy A Osajima; Adriel da Silva Almeida; Thiago M B F Oliveira; Jefferson F D F Araujo; Suellen D T de Barros; Marcelo E H Maia da Costa; Diego A B Barbosa; João V B Moura; Gardênia S Pinheiro; Cleânio L Lima

doi:10.1021/acsomega.4c08777

Preparation and Application of Sodium-Lanthanum Molybdate for the Photocatalytic Degradation of Coomassie Brilliant Blue G-250 Dye

ACS Omega. 2025 Apr 17;10(16):16006-16014. doi: 10.1021/acsomega.4c08777. eCollection 2025 Apr 29.

Authors

Caique D A Lima^{1

2}, Joyce A Borges^{3

4}, Italo A L Santos¹, Angel A Hidalgo¹, Josy A Osajima³, Adriel da Silva Almeida⁵, Thiago M B F Oliveira⁵, Jefferson F D F Araujo², Suellen D T de Barros², Marcelo E H Maia da Costa², Diego A B Barbosa⁶, João V B Moura⁶, Gardênia S Pinheiro¹, Cleânio L Lima¹

Affiliations

¹ Department of Physics, Campus Universitário Ministro Petrônio Portella, Universidade Federal do Piauí, Bairro Ininga, Teresina PI CEP: 64.049- 550, Brazil.
² Department of Physics, Pontifical Catholic University of Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, Brazil.
³ Laboratório de Materiais Avançados - Limav, Campus Universitário Ministro Petrônio Portella, Universidade Federal do Piauí, Bairro Ininga, Teresina PI CEP: 64.049- 550, Brazil.
⁴ Department of Chemistry, Campus Universitário Ministro Petrônio Portella, Universidade Federal do Piauí, Bairro Ininga, Teresina PI CEP: 64.049- 550, Brazil.
⁵ Science and Technology Center, Federal University of Cariri, Av. Tenente Raimundo Rocha, 1639, Cidade Universitária, Juazeiro do Norte 63048-080, CE, Brazil.
⁶ Department of Physics, Federal University of Maranhão, São Luís 65080-805, MA, Brazil.

Abstract

This study reports on the synthesis, characterization, and application of sodium-lanthanum molybdate [NaLa(MoO₄)₂] as a photocatalyst in the degradation process of Coomassie Brilliant Blue G-250 (CBB-250), an environmentally toxic and recalcitrant dye derived from triphenylmethane. The highlighted ceramic material was produced by coprecipitation, and its properties were studied using a range of physicochemical techniques including compositional, crystallographic, and morphological analyses. Among the most relevant information, X-ray diffraction (XRD), Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy confirmed the formation of NaLa (MoO₄)₂ crystals with a tetragonal arrangement. Additionally, the scanning electron microscope (SEM) images provide evidence of the production of overlapping plate-like microstructures. The nitrogen adsorption isotherms demonstrated that the molybdate obtained exhibits mesoporous organization, with a surface area and pore diameter equivalent to 45.7 m² g^-1 and 6.54 nm, respectively. Photocatalytic tests, performed under ultraviolet light irradiation for 120 min, indicated that NaLa(MoO₄)₂ has high oxidative reactivity, achieving a degradation of >95% of the CBB-250 dye present in the system. The reaction velocity constants, estimated in accordance with the Langmuir-Hinshelwood equation, substantiate that NaLa(MoO₄)₂ enhances the reaction kinetics (13.7 × 10^-3 min^-1) throughout the photochemical treatment. In light of the growing scientific interest in effective strategies for the removal of emerging pollutants from contamination matrices, NaLa(MoO₄)₂ represents a promising avenue for the development of innovative technologies in this field.