Catalysis based on two-dimensional silicon has been under intense investigation recently. However, its substandard catalytic activity is far from industrialization. In this work, we demonstrate a new solution to this problem formulated on the batch synthesis of siloxene with an enhanced specific surface area (217.8 m 2 g -1 ). A two-dimensional porous structure was prepared, enabling great support and dispersion of metal nanoparticles. Catalytic evaluations of such hybrid structures for the (photo)thermal CO 2 hydrogenation reaction and the electrochemical hydrogen evolution reaction revealed a significant performance advantage over the benchmark two-dimensional silicon structures synthesized via the conventional method. This work may confer notable viability on two-dimensional silicon for advanced energy, catalytic, and environmental applications.