MXene quantum dots decorated Ni nanoflowers for efficient Cr(VI) reduction

Nickel@MXene quantum dots (Ni@MQDs), as novel flower-like hybrid materials, were firstly prepared through a simple reduction method. The Ni@MQDs exhibited an outstanding catalytic performance for Cr (VI) reduction with a low activation energy (E-a = 18.9 kJ mol(-1)) and a high kinetic constant (k = 0.4779 min(-1)) in the presence of formic acid (HCOOH). Density functional theory calculations demonstrated that Ni@MQDs exhibited an upshift of D-band center of active Ni atoms to promote the adsorption of both HCOOH and active H atoms, as well as an improved conductivity to boost the catalytic reaction kinetics, leading to the most favorable catalytic performance. This work may open up a new avenue towards the design and synthesis of novel MQDs-based hybrid catalysts for wastewater treatment.

Automated summary

Nickel@MXene quantum dots (Ni@MQDs) were successfully prepared and showed outstanding catalytic performance for Cr (VI) reduction in the presence of formic acid. Density functional theory calculations revealed that Ni@MQDs exhibited an upshift of D-band center of active Ni atoms, leading to improved catalytic reaction kinetics. This work may pave the way for the design and synthesis of novel MQDs-based hybrid catalysts for wastewater treatment.