<p>Rapid industrialization in recent years has resulted in the generation of large quantities of hazardous organic pollutants. These pollutants threaten human and ecosystems. Thus, treatment of them from wastewater is mandatory. Accordingly, solar light active Au-doped BiOCl@black TiO₂ (Au/BiOCl@b-TiO₂) nanocomposites were designed and developed by considering good photocatalytic activity but insufficient solar light absorption of BiOCl, excellent wide range light absorption of black TiO₂, and good visible light absorption and charge transfer property of plasmonic noble metal Au. Moreover, the preparation method of b-TiO₂ in this work was free of use of H₂ unlike to the reported literature, which makes it safe and ecofriendly technique. The synthesized samples were systematically examined using available precision instruments. The photocatalytic property of the as-prepared photocatalysts was explored toward photodegradation of organic dye rhodamine B (RhB) as model pollutant. The findings confirm that the developed Au/BiOCl@b-TiO₂ nanocomposites showed excellent photocatalytic activity by degrading 98% of 30&#xa0;ppm RhB just in 2&#xa0;h. Its photocatalytic activity was compared with open literature, and it presented better photocatalytic ability than that of the reported solar light active photocatalysts. The active species trapping experiment reveals that holes and superoxide radicals are responsible for the photodegradation of RhB. The outstanding photocatalytic property of the fabricated Au/BiOCl@b-TiO₂ nanocomposites could be ascribed to the extended optical absorption, suppression of charge recombination, and p–n heterojunction formation. Hence, the developed Au-doped BiOCl@b-TiO₂ nanocomposites show promise in the treatment of this organic pollutant, contributing significantly to the environmental remediation in general, and photocatalysis in particular.</p>