  Citation: Khan, M.U.; Du, L.; Fu, S.; Wan, D.; Bao, Y.; Feng, Q.; Grasso, S.; Hu, C. Preparations and Applications of MXene–Metal Composites: A Review. Coatings 2022, 12, 516. https://doi.org/10.3390/ coatings12040516 Academic Editor: Alexandru Enesca Received: 28 February 2022 Accepted: 6 April 2022 Published: 11 April 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). coatings Review Preparations and Applications of MXene–Metal Composites: A Review Maaz Ullah Khan 1 , LiJing Du 1 , Shuai Fu 2 , Detian Wan 2 , Yiwang Bao 2 , Qingguo Feng 1 , Salvatore Grasso 1 and Chunfeng Hu 1, * 1 Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China; engrmaaz213@gmail.com (M.U.K.); dulijing3933@163.com (L.D.); qfeng@swjtu.edu.cn (Q.F.); s.grasso@swjtu.edu.cn (S.G.) 2 State Key Laboratory of Green Building Materials, China Building Materials Academy, Beijing 100000, China; shuaifu19@163.com (S.F.); dtwan@ctc.ac.cn (D.W.); ywbao@ctc.ac.cn (Y.B.) * Correspondence: chfhu@live.cn Abstract: MXene, an advanced family of 2D ceramic material resembling graphene, has had a consid- erable impact on the field of research because of its unique physiochemical properties. MXene has been synthesized by the selective etching of MAX via different techniques. However, with the passage of time, due to the need for further progress and improvement in MXene materials, ideas have turned toward composite fabrication, which has aided boosting the MXene composites regarding their properties and applications in various areas. Many review papers are published on MXene and their composites with polymer, carbon nanotube, graphene, other carbon, metal oxides and sulfides, etc., except metal composite, and such papers discuss these composites thoroughly. In this review article, we illustrate and explain the development of MXene-based metal composites. Furthermore, we highlight the synthesis techniques utilized for the preparation of MXene composites with metal. We briefly discuss the enhancement of properties of the composites and a wide range of applications as an electrode substance for energy storage devices, electrochemical cells, supercapacitors, and catalytic and anti-corrosive performance. Major obstacles in MXene and metal composite are mentioned and provide futurerecommendations. Together, they can overcome problems and enable MXene and composites on commercial-scale production. Keywords: MXene; metals; composite; properties; applications 1. Introduction The development of new advanced materials is highly demanded by the aerospace and automotive industries, which come up with weight savings, boost energy efficiency, resist severe structural loadings, and increase tribological performances. To accomplish such particular features, the material should have high specific strength, elastic modulus, and stiffness additional to improved functional characteristics [1]. Two-dimensional (2D) materials have been described as an acceptable constituent in future electrical properties, and their mechanical properties are entirely predominant for several approaches. The explo- ration of the mechanical properties and associated atomic structure are slightly troublesome because of their atomic breadth and planar character [2]. Two-dimensional materials mostly possessed a layered structure, which made them distinct from three-dimensional (3D) crys- talline and one-dimensional (1D) nanowires. Two-dimensional substances are composed of covalent bonds in every layer and are packed cooperatively with van der Waals interactions. This crystal structure can provide these 2D substances with distinctive elastic, fracture, surface, and interfacial properties [3]. The developing method of two-dimensional (2D) graphene was examined to be complex and costly, which restricted its feasible practical im- plementations [4]. MXene, a newly produced class of 2D materials from Drexel University, has so far achieved superior consideration in the science world. Commonly, MXenes are Coatings 2022, 12, 516. https://doi.org/10.3390/coatings12040516 https://www.mdpi.com/journal/coatings