Decorating nitrogen-deficient crystalline g-C3N4 with Ti3C2(OH)2 for photocatalytic CO2 reduction and RhB degradation enhancement

Visible light responding photocatalytic technology has shown great potential to mitigate the greenhouse effect and global pollution issues in recent years. Herein, alkalized titanium carbide Ti3C2Tx (TCOH) is combined with nitrogen-deficient g-C3N4 (CN-N-x) by simply mixing for photocatalytic CO2 reduction and RhB degradation. TCOH replaces noble metals as a co-catalyst for CN-N-x due to its full-spectrum absorption properties and excellent conductivity, which effectively enhances the overall light absorption capacity of CN-N-x. Additionally, a large Fermi energy level difference between TCOH and CN-N-x leads to a built-in electric field forming at their interface when combined. This built-in electric field can enhance the photogenerated electron-hole pair separation and reduce the recombination rate. So the visible light utilization ranges of optimized 2TCOH-30 %/CN-N-0.02 expanded from 477 nm (CN-N-0.02) to 481 nm, and the average lifetimes of the photogenerated carriers is 4.37 ns, which is 2.64 times longer than CN-N-0.02. Moreover, the CO yield reaches 67.55 mu mol/g during photocatalytic CO2 reduction of 2TCOH-30 %/CN-N-0.02, which is 4.06 and 2.54 times than 2TCOH and CN-N-0.02. During the RhB degradation, 2TCOH-30 %/CN-N-0.02 can remove approximately 98.3 % of RhB in 15 min, which is1.6 and 1.4 times of 2TCOH and CN-N-0.02. Also, 2TCOH-30 %/CN-N-0.02 shows excellent stability, the photocatalytic capacity for CO2 reduction and RhB degradation has no significant degradation after six times circles.