*6.6. Silicene*

After the discovery of graphene, as an element of the same family of carbon, silicene was naturally noticed. However, it was not until 2012 that silicene was synthesized, and the growth conditions were too harsh [183,184]. Therefore, the thermal conductivity of silicene is still in theoretical research and there has been no progress in experimental research. In addition to the intrinsic thermal conductivity, theoretically, the use of stress, electric fields, defects, isotopes, and other methods to control the thermal conductivity of silicene has been studied in theory, which will provide guidance for future experimental research of silicene.

#### *6.7. Other 2D Materials*

With the continuous development of nanomaterial preparation technology and computational simulation technology, the family of two-dimensional materials is becoming larger and larger. Not only can a new type of two-dimensional material be synthesized experimentally, but it is also possible to predict some unknown two-dimensional materials through theoretical simulation. In addition to the above-mentioned materials, there are many other two-dimensional materials whose thermal conductivity properties have also been studied. In terms of experiments, researchers have used different methods to measure multi-layer

bismuth telluride [185], multi-layer indium selenide [186], and the in-plane thermal conductivity of two-dimensional materials such as multi-layer tin sulfide [187], zirconium telluride [83], and multi-layer bismuth selenium oxide [188]. Thermal conductivity and related properties of two-dimensional materials such as gallium nitride [189], boronene [190], single-layer carbon nitride [191], and single-layer nitrogen boron carbide [192] have also been studied.
