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 H-2 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 H-2 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.