Enhanced Photocatalytic Degradation of Emerging Contaminants Using Ti₃C₂T_x MXene-Supported CdS Quantum Dots

Abstract

The synthesis of efficient and stable catalysts for photocatalytic reactions is still a challenge. In this study, a new photocatalyst composed of two-dimensional titanium carbide (Ti3C2T x ) and CdS quantum dots (QDs) was fabricated, in which CdS QDs were intimately anchored on the Ti3C2T x sheet surface. Due to the specific interface characteristics of CdS QDs/Ti3C2T x , Ti3C2T x can considerably facilitate the generation of photogenerated charge carriers, their separation, and their transfer from CdS. As expected, the obtained CdS QDs/Ti3C2T x exhibit outstanding photocatalytic performance for carbamazepine (CBZ) degradation. Moreover, the quenching experiments demonstrated that superoxide radicals (•O2 –), H2O2, 1O2, and •OH are the reactive species involved in CBZ degradation, while •O2 – made a major contribution. In addition, the sunlight-driven CdS QDs/Ti3C2T x photocatalytic system is widely suitable for the elimination of different emerging pollutants in various water matrices, suggesting its potential practical environmental applications.

A H2O2 Oxidation Approach to Ti3C2/TiO2 for Efficient Photocatalytic Removal of Distinct Organic Pollutants in Water

“…The EPR profiles of the Ti 3 C 2 /TiO 2 derived by calcination at 500–600 °C, using DMPO as a trapping agent, were achieved to evaluate the ·O 2 – concentration . The Ti 3 C 2 /TiO 2 obtained at 550 °C have a slightly lower ·O 2 – concentration compared to those obtained at 500 and 600 °C (Figure e).…”

“…In 2011, Naguib et al used HF to selectively etch away the metal Al layer in the ternary layered intermetallic compound Ti 3 AlC 2 and successfully prepared two-dimensional Ti 3 C 2 MXene materials. , Since then, these MXene materials of two-dimensional transition metal carbide or carbon-nitride have found wide applications in the environment and energy region because of their unique graphene-like structure and excellent physicochemical properties. − In photocatalysis, Ti 3 C 2 MXenes enable the rapid migration of electrons, which inhibits the electron–hole recombination of TiO 2 and in turn enhances its photocatalytic performance. The Ti 3 C 2 MXene composited TiO 2 , and that further composited with other semiconductors like CdS, , ZnIn 2 S 4 , and C 3 N 4 , , or other materials of rGO or precious metals , have thus received attention in recent years. Ti 3 C 2 MXene is prone to oxidation because of its surface functional groups (such as −OH, −F) and multilayered structure that makes it prone to oxidative reactions when exposed to oxygen.…”

“…5−9 In photocatalysis, Ti 3 C 2 MXenes enable the rapid migration of electrons, which inhibits the electron−hole recombination of TiO 2 and in turn enhances its photocatalytic performance. The Ti 3 C 2 MXene composited TiO 2 10,11 and that further composited with other semiconductors like CdS, 12,13 ZnIn 2 S 4 , 14 and C 3 N 4 , 15,16 or other materials of rGO 17 or precious metals 18,19 have thus received attention in recent years. Ti 3 C 2 MXene is prone to oxidation because of its surface functional groups (such as −OH, −F) and multilayered structure that makes it prone to oxidative reactions when exposed to oxygen.…”

Highly Efficient Photocatalytic H2O2 Production over a Zn0.3Cd0.7S/MXene Photocatalyst for Degradation of Emerging Pollutants under Visible-Light Irradiation

“…Furthermore, the in situ generation of H 2 O 2 was further used to degrade various pharmaceutical and personal care product (PPCP) pollutants, such as sulfamethoxazole (SMX), carbamazepine (CBZ), sulfamethazine (SMT), and bisphenol A (BPA), since they are emerging pollutants that have the potential to pose hazards to both the environment and human health. ,− First, the photodegradation of different pollutants by ZCM-0.3 alone was researched. As illustrated in Figure a, the degradation efficiencies of SMX, SMT, CBZ, and BPA by ZCM-0.3 alone were 81.44, 43.81, 38.39, and 13.75%, respectively.…”

MXene/CdS photothermal–photocatalytic hydrogels for efficient solar water evaporation and synergistic degradation of VOC

“…The coupling of Ti 3 C 2 MXene and CdS may form a tight interface between the two, through which photogenerated electrons can easily quickly hop to Ti 3 C 2 MXene (eqn (3)). 21,40,61 Therefore, Ti 3 C 2 MXene can act as a charge transfer medium and electron capture site, accelerating the separation of electrons and holes and extending the lifetime of photocarriers. 62 Subsequently, electrons migrating to the surface of Ti 3 C 2 MXene can further induce the formation of a range of ROS.…”