Abstract
<title>Abstract</title> <p> This study reports the synthesis of pure copper oxide and CuO hydrogels with lanthanum-based compounds to investigate how lanthanum incorporation affects their structural, optical, surface, antimicrobial and catalytic behaviour. A comparison showed that the functional performance of CuO hydrogels is significantly enhanced by doping with lanthanum. Compared to pure CuO, the La-doped samples showed markedly stronger antibacterial activity against both Gram positive and Gram negative bacteria. This effect was attributed to an increase in reactive oxygen species (ROS) production and an increase in Cu <sup>+</sup> ion release, both of which impaired the bacterial membranes and inhibited microbial growth. In addition, the hydrolysis of the La-doped CuO showed extraordinary catalytic activity in the degradation of the Rhodamine B dye, removing 99.9% of the dye in only 8 minutes. Activation parameters regulating the catalytic process have been identified by analysis of <bold>Arrhenia and ocular sites</bold> as well as kinetic studies performed under different conditions. The calculated activation energy (E <sub>a</sub> ) of 48.42 kJ mol <sup>− 1</sup> , activation enthalpy (ΔH) of 43.78 kJ mol <sup>− 1</sup> and activation entropy (ΔS) of 271.42 J mol <sup>− 1</sup> support an energetically favourable and efficient catalytic reaction. All these results indicate that lanthanum doping significantly improves the antibacterial and catalytic activity of CuO hydrogues by altering their physicochemical properties. Lanthanum-doped CuO hydrogels are an interesting multifunctional material for environmental remediation, in particular for the treatment of waste water and for antimicrobial applications due to their rapid dye degradation, strong bactericidal activity and favourable kinetic and thermodynamic properties. They are attractive options for sustainable environmental and bio-medical technologies because of their high efficiency and environmental friendliness. </p>