Nitrogen-Doped Ti₃C₂ MXene Quantum Dots/1D CdS Nanorod Heterostructure Photocatalyst of Highly Efficient Hydrogen Evolution

Abstract

Solar-driven photocatalytic hydrogen production is considered an effective strategy to mitigate the current energy and environmental challenges. Herein, a function heterostructure photocatalyst of 1D CdS nanorod rationally supported nitrogen-doped Ti3C2 MXene quantum dots (N-MQDs) is successfully constructed via the self-assembly strategy. Impressively, N-MQDs/CdS exhibits superior photocatalytic hydrogen production performance with an efficiency rate of 17094 μmol g–1 h–1, which is 14.79 times higher than pure CdS. The strong oxidizing performance of N-MQDs/CdS also presents an efficient activity for the photodegradation of phenol. The significant enhancement in performance is mainly due to the synergistic effect of the tight interfacial contact and matched energy levels between the highly conductive Ti3C2 MXene quantum dots and 1D CdS nanorod, which greatly accelerates the separation and transfer of photogenerated carriers. Regulating the energy band structure of photocatalysts via multifunctional MXene materials could hopefully motivate further interest in the reasonable design of MXene-semiconductor photocatalytic materials in energy and environmental applications.

Recent Advances in the Synthesis of MXene Quantum Dots

“…used to solvothermal method to obtain the Ti 3 C 2 Tx QDs that can be employed as a 3D‐printed electrochemical sensor for the detection of dopamine [85] . In addition, the Ti 3 C 2 MXene QDs can also be considered as a support to form a function heterostructure with 1D CdS nanorod for photocatalysis to hydrogen production [86] . Notably, the solvothermal method usually forms the by‐product of carbon quantum dots (CQDs) due to the carbonization of the organic solvent precursor, which may affect the service performance of the MXene QDs [5,47,51] …”

Nitrogen‐Doped Electrocatalysts, and Photocatalyst in Water Splitting: Effects, and Doping Protocols

“…As an example of the direct synthesis, heating, and then calcining the mixture of ethylenediamine or ammonium chloride with InCl 3 gave In 2 O 3 . [64] Annealing trimethylamine/TiO 2 in NH 3 or N 2 furnished N-TiO 2 via the post-modification reaction. [56] Moreover, thermal treatment is a common condition for the synthesizing all the N-doped photocatalysts.…”

“…The highest water splitting rate was observed for N‐doped TiO 2 with (211) orientation, revealing the remarkable impact of facets on the reaction yield [55] . A new form of Ti known as N‐doped Ti 3 C 2 MXene QDs composed with CdS nanorod was also applied in water splitting with a remarkable performance of 17094 mumol g −1 h −1 , which was 14.79 times higher than pure CdS [64] . While CdS is considered as one of the powerful semiconductors, N‐CdPS 3 also showed a remarkable potential for the water splitting with the bandgap of 2.99 eV [65] …”

“…N doping into water splitting photocatalysts was conducted by the direct synthesis or post‐modification reaction similar to N doping into electrocatalysts. As an example of the direct synthesis, heating, and then calcining the mixture of ethylenediamine or ammonium chloride with InCl 3 gave In 2 O 3 [64] . Annealing trimethylamine/TiO 2 in NH 3 or N 2 furnished N‐TiO 2 via the post‐modification reaction [56] .…”

“…[55] A new form of Ti known as N-doped Ti 3 C 2 MXene QDs composed with CdS nanorod was also applied in water splitting with a remarkable performance of 17094 mumol g À 1 h À 1 , which was 14.79 times higher than pure CdS. [64] While CdS is considered as one of the powerful semiconductors, N-CdPS 3 also showed a remarkable potential for the water splitting with the bandgap of 2.99 eV. [65] N doping on ZnO composites were also investigated for the synthesis of the water splitting photocatalysts, in which all of Table 5.…”