Graphite-like C3N4 （g-C3N4） is an efficient visible-light-driven photocatalyst which is com- monly used in pollutant degradation. The photoreactivity of g-C3N4 depends on the prepa- ration conditions to a large extent. In this work, we linked the preparation conditions of g-C3N4 to its stability and photocatalytic activity through dye photodegradation experiments and sensitivity mathematical analyses. The sensitivity mathematical analyses show that the effect of calcination temperature is more significant than calcination time on the photoreactivity of g-C3N4. The photocatalytic activity of optimized g-C3N4 in rhodamine B （RhB） degradation under visible light was 100 times higher than that of non-optimized one. The enhanced performance can be attributed to the increased specific surface area of g-C3N4 and the increased migration velocity of photogenerated electron-hole pairs on the surface. This work deepens the understanding of the relation between preparation conditions and the charateristics of g-C3N4, and provides an extremely simple method for significantly improving the photoreactivity of g-C3N4.
