Stacking-Layer-Number Dependence of Water Adsorption in 3D Ordered Close-Packed g-C₃N₄ Nanosphere Arrays for Photocatalytic Hydrogen Evolution

Water adsorption capacity is a key factor to influence the photocatalytic H₂ evolution activity of polymeric g-C₃N₄. Herein, we report the synthesis of 3D ordered close-packed g-C₃N₄ nanosphere arrays (CNAs) that significantly enhance the water adsorption capacity. Through precisely controlling the average stacking-layer number (ASLN) of the nanospheres in CNAs, we reveal an interesting stacking-layer-number dependence of water adsorption in the newly designed CNAs for accelerating the H₂ evolution reaction, which can be attributed to the differences in adsorption surface areas and adsorption sites endowed by the point-defect cavities in sample CNAs.