<p>This study explores the sustainable fabrication of magnesium oxychloride cement (MOC) using reactive MgO derived from dolomite, coupled with photocatalytic and supplementary cementitious materials to optimize both mechanical and self-cleaning performance. The novelty of this work lies in the development of a simple and environmentally friendly glucose-assisted method to obtain high-purity reactive MgO from dolomite using a 2^5-1 design of experiments, enabling the production of self-cleaning MOC using a non-traditional and abundant magnesium source. This process represents a new strategy to design multifunctional and eco-efficient MOC. The incorporation of TiO₂ into the MOC enhanced light absorption, while combinations with slag or fly ash modulated photocatalytic activity. Under simulated sunlight, the photocatalytic cements outperformed unmodified MOC, with fly ash-based systems achieving the highest self-cleaning efficiency and excellent moisture stability (&gt;92%). These results demonstrate that the extraction of MgO from a natural source with functional additives provides a viable route to engineer durable, photoactive, and eco-efficient MOC materials for sustainable construction.</p> Graphical abstract <p></p>