One-step synthesis of rice husk carbon with dangling CC bonds loaded g-C3N4 for enhanced photocatalytic degradation

Metal-free graphitic carbon nitride (g-C3N4) should be an ideal candidate for photocatalytic degradation of pollutants. However, its performance is limited by low adsorption and high recombination rate of electron-hole pairs. Herein, g-C3N4 nanosheets were highly dispersed on rice husk carbon (CN@RHC) by one-step sealed calcination. The specific surface area was greatly increased from 7.7 to 137 m(2)/g, which improves the adsorption performance. Abundant dangling CC bond defects of rice husk carbon were confirmed by electron paramagnetic resonance, which played an important role of electron acceptor and effectively inhibit the recombination of photogenerated carriers. As a result, 98% of Methylene blue was removed in 4.5 h using a 5 W light emitting diode source with visible light while only 80% of that was removed by bulk g-C3N4. The degradation performance was enhanced by the synergism of excellent adsorption performance and better photogenerated carriers transport performance. Based on the simple synthesis method, low cost and excellent visible photocatalytic performance, dangling CC bonds should be the focus for promoting photocatalysis as well as improve the added value of agricultural waste. (c) 2020 Elsevier Ltd. All rights reserved.