Progress and challenges of emerging MXene based materials for thermoelectric applications

Beyond metals: theoretical discovery of semiconducting MAX phases and their potential application in thermoelectrics

“…50 Recent research findings indicate that the thermoelectric figure of merit ( zT ) of MXenes is predominantly below 1, as supported by several studies. 51–56 However, there are exceptions such as Cr 2 TiC 2 (OH) 2 , 57,58 ScYCT 2 (T = F, OH), and TiMCO 2 (M = Zr, Hf), 59 where zT values can exceed 1 within the temperature range of 300–900 K, and 59 also exhibit zT values greater than 1 within the temperature range of 300–900 K. 60 It is important to note that despite these promising zT values, most synthesized MXenes tend to be metallic in nature. For instance, the power factors reported for Mo-based MXenes (Mo 2 CT x , Mo 2 TiC 2 T x , and Mo 2 Ti 2 C 3 T x ) are as low as 3.09 × 10 −4 W m −1 K −2 at 803 K, indicating a relatively low thermoelectric efficiency for metallic MXenes.…”

Deep eutectic solvents as an emerging green platform for the synthesis of functional materials

“…Conventional etching of MXene can be done using HF etching, fluorine salt enhanced acid, electrochemical etching, hydrothermal etching, and molten salt etching. 194 Of course, there are also teams using DESs for etching, for example, Gong et al 195 used a choline chloride and urea-based DES to etch Ti 3 C 2 Al. In addition, Wu et al 196 designed a deep eutectic solvent (DES) with choline chloride and oxalic acid-based solvothermal methods to etch Ti 3 C 2 Al.…”

Recent progress of poly(3-hexylthiophene)-based materials for thermoelectric applications

“…Many inorganic materials such as metal chalcogenides ( e.g. , Cu 2 S 17 , Cu 2 Se 18 , SnS 2 19 , SnSe 20 , Cu 3 SbS 4 , 21 CsCu 5 S 3 , 22 Bi 2 O 2 Se 23 , Bi 2 Te 3 24 , and PbTe 25 ), 2D MXenes, 26,27 conducting oxides ( e.g. , SrTiO 3 ), 28 half-Heusler alloys ( e.g.…”

“…, and PbTe 25 ), 2D MXenes, 26,27 conducting oxides (e.g., SrTiO 3 ), 28 half-Heusler alloys (e.g., TiNiSn and ZrNiSb), 29,30 and composites (e.g., porous silicon loaded with Ag) 31 exhibit high-efficiency thermoelectric properties. However, these materials suffer from the disadvantages of less abundant elements and high toxicity.…”