Fig. 8

a Photocatalytic H2 evolution rate as a function of irradiation time of 5Â h over LNO, CN and LNCN [2,3,4,5,6,7,8]; b Photocatalytic H2 evolution rate for three repeated tests over samples with different content of g-C3N4 and the corresponding standard deviation map; c Long-term stability test of LNCN7 composite for 20Â h