Effective Surface Modification of 2D MXene toward Thermal Energy Conversion and Management

Abstract

Thermal energy management is a crucial aspect of many research developments, such as hybrid and soft electronics, aerospace, and electric vehicles. The selection of materials is of critical importance in these applications to manage thermal energy effectively. From this perspective, MXene, a new type of 2D material, has attracted considerable attention in thermal energy management, including thermal conduction and conversion, owing to its unique electrical and thermal properties. However, tailored surface modification of 2D MXenes is required to meet the application requirements or overcome specific limitations. Herein, a comprehensive review of surface modification of 2D MXenes for thermal energy management is discussed. First, this work discusses the current progress in the surface modification of 2D MXenes, including termination with functional groups, small‐molecule organic compound functionalization, and polymer modification and composites. Subsequently, an in situ analysis of surface‐modified 2D MXenes is presented. This is followed by an overview of the recent progress in the thermal energy management of 2D MXenes and their composites, such as Joule heating, heat dissipation, thermoelectric energy conversion, and photothermal conversion. Finally, some challenges facing the application of 2D MXenes are discussed, and an outlook on surface‐modified 2D MXenes is provided.

Recent Progress in MXene‐Based Electrochemical Actuators and Capacitors

“…[ 20 ] Meanwhile, molybdenum or niobium‐based MXene, such as Mo 2 C or Nb 2 C, respectively, showed potential in thermoelectric energy harvesting applications. [ 13 ]…”

“…[ 8 ] Because of these advantages, MXenes have been widely adopted in various applications such as energy storage and harvesting, biomedicine, sensor, actuator, and electromagnetic shielding applications. [ 8,10–13 ]…”

Ti3C2 MXene Nanosheet-Based Dual-Enzyme Cascade Reaction to Facilitate Dual-Stimulation-Mediated Breast Cancer Therapy

“…Among them, light-responsive drug delivery platforms are the most widely studied applications. , Recently, MXene nanosheet has become a leader in 2D structures due to its unique physicochemical properties, high stability, and excellent biocompatibility for the preservation of catalytic activity. , Among the large MXene nanosheet family, as the first discovered and most used MXene, titanium carbide (Ti 3 C 2 ) nanosheets have outstanding photothermal conversion ability and release huge heat after NIR irradiation, which is often used for effective photothermal therapy (PTT) of tumors. − Not only that, based on the advantages of the ultrathin planar nanostructure and corresponding specific surface area of Ti 3 C 2 , they are further developed into drug delivery nanosystems for cancer chemotherapy, which are popular nanomaterials used in combination therapy today. − However, the terminal functional group −OH of Ti 3 C 2 is very unstable and easily oxidized and deposited, which also greatly limits its drug loading capacity. APTES as a surfactant can change the terminal −OH to −NH 2 , which is more favorable for subsequent drug loading. − Additionally, loading Ti 3 C 2 with GOX is an ingenious idea to perfectly blend GST and PTT. GST can reduce the ATP level by draining the tumor glucose level, down-regulate the overexpressed heat shock proteins in the tumor site, and improve the PTT efficiency of tumor cells.…”

Plasmon assisted Ti3C2Tx grafting and surface termination tuning for enhancement of flake stability and humidity sensing performance

“…Commonly, high energy treatments, such as temperature annealing or plasma processing, are used to tune the surface chemistry of MXenes. 10,35–37 However, such rough methods can damage the MXenes structure and lead to a loss of functionality of the flakes. As an alternative, few chemical approaches capable of changing the flakes surface composition were proposed.…”