Designing and simulating an effective photocatalytic material having a suitable bandgap to degrade organic pollutants is essential for environmental remediation. This paper describes the development of a class of nanostructure, La2Cu2O5, for photocatalytic decomposition of various types of organic pollutants under UV and visible lights. La2Cu2O5 nanostructures were synthesized by a rapid and environmentally friendly sonochemical technique for the first time. The impacts of molar ratio of precursors, calcination temperature, power, and time of sonication were scrutinized for the synthesis of La2Cu2O5 nanostructures with relevant attributes in terms of purity, particle size, and morphology. The bandgap of these nanostructures was calculated at 3.25 eV, making them profitable for contaminant degradation in the UV region. The photocatalytic activity of the desired La2Cu2O5 was examined for photodegradation of multiple pollutants, such as thymol blue, acid black, methyl violet, rhodamine B, phenol red, malachite green, acid Yellow, and erythrosine for the first time. The La2Cu2O5 nanocatalyst revealed premium performance over the degradation of the mentioned pollutants. La2Cu2O5 was capable of degrading the acid black contaminant better (80.1%). The highest photocatalytic efficiency was obtained at a greater rate constant reaction (k = 0.01332 min−1).