Meet the editor

Dr. Ing. Abdelfatteh Haidine is Professor Habilité at the University of Applied Sciences, El Jadida, Morocco. He is a member of the Laboratory of Information Technologies at the same university. His research interests include the simulation and evaluation of wireless and mobile networks, as well as design (network planning/migration and resources allocation) and evaluation of communication networks for smart environments, especially

smart cities, smart grids, smart maritime ports, and smart environment monitoring. He holds a Ph.D. from Technische Universität Dresden, Germany. His Ph.D. studies focused on the planning and optimization of communication networks utilizing combinatorial optimization and multi-objective optimization/ multi-criteria decision-making. Dr. Haidine has worked on different European research and industry projects as well as with various companies as a consultant for intelligent network communications, with a focus on the planning of communication solutions for power utilities to build smart grid communication platforms. His tasks covered technical specifications, planning and performance evaluation of communication solutions, as well as techno-economics aspects for smart grid projects.

## Contents

Preface

Vehicles play a crucial role in modern society, contributing significantly to various aspects of life. Vehicles provide mobility for people and goods, facilitating travel and transportation of goods over short and long distances. They enable commuting to work, school, healthcare facilities, and recreational activities, thus enhancing overall accessibility and quality of life. The automotive industry is a major contributor to the global economy. It creates millions of jobs worldwide, directly and indirectly, in manufacturing, sales, services, and related sectors. Additionally, vehicles support other industries by transporting raw materials and finished goods, fostering economic

Vehicles ushered in the era of autonomy, first through assisted driving and second with the goal of reaching full autonomy in driving, parking, and so on. Vehicles face numerous challenges, ranging from technological limitations to social and environmental concerns. Addressing these challenges requires a holistic approach involving collaboration between governments, industry players, academia, and civil society to

As part of this innovation, vehicular networks based on vehicular communications, also known as V2X (Vehicle-to-Everything) communication, refers to the exchange of data between vehicles (V2V), infrastructure (V2I), pedestrians (V2P), and other entities such as cyclists and road operators (V2R). This communication enables vehicles to interact with their surroundings, improving safety, efficiency, and convenience on

This book discusses different aspects related to vehicular networks. It is organized into two sections. The first section, "Application Fields", begins with Chapter 1, "Introductory Chapter: Vehicles Everywhere, and Vehicular Communications Should Follow!". The introductory chapter gives an overview of the different and most recent and innovative applications of modern industries for vehicles, such as automated guided vehicles (AGV) in smart maritime ports or in logistics companies, and more. The main idea of this introduction is that where we have vehicles, we should also have vehicular networks, which are necessary to overcome some of the previously cited challenges. Chapter 2, "C-V2X Vision in the Chinese Roadmap: Standardization, Field Tests, and Industrialization", analyzes activities and applications of vehicular communications in the special case of China, which is a large country with a large population and huge number of used vehicles either in private lives or industries. China continuously and actively focuses on and contributes to C-V2X technology development. Starting from the standardization progress, the chapter presents several Chinese-specific use cases and communication messages for complicated urban traffic. Based on these higher-layer protocols, annual field tests are conducted to determine the interoperability among chipsets, modules, security certificates, and original equipment manufacturers (OEMs). Putting forth effort on industry standards and tests, China is fast commercializing C-V2X

foster innovation, sustainability, and resilience in the automotive sector.

growth and development.

the road.


*3.1.2 Annealing*

An important step prior to the CVD synthesis of graphene is the thermal treatment of the micrometer-thick Cu foils. Cu substrates undergo an annealing process that consists of heating them at high temperatures close to the Cu melting point, but lower than it (<1,085°C) for a certain period of time [25]. The surface of copper has some roughness, grain boundaries, surface defects, and impurity particles. This process is carried out in order to smooth the copper surface, reduce surface oxides, remove volatile impurities and surface contaminants, and favor the formation of graphene on the surface [26]. In addition, a reorganization of the copper atoms on the surface is promoted, which produces a release of internal stresses and an increase in the size of the Cu microcrystalline structure [25].

Regarding graphene nucleation, flat Cu regions, or terraces, favor the growth of SLG or BLG domains. In contrast, slope regions on the Cu surface, or ledges, promote MLG growth. Additionally, grain boundaries, impurities, and surface defects contribute to the formation of MLG domains [26].

#### **3.2 Precursors**

The synthesis of graphene using the CVD technique can be carried out with a large catalogue of carbon-based compounds used as precursors. These precursors can be categorized by their physical state or by their chemical structure. By physical state, they can be classified as gaseous, liquid, and solid. While based on its chemical structure, they are separated as aliphatic and aromatic compounds. The use of an appropriate precursor with the right conditions can improve the efficiency of the production process and the quality of the final product [15].

#### *3.2.1 Gases*

Gaseous carbon precursors are the main source used for graphene synthesis by CVD. The most used are hydrocarbons such as methane (CH4) and acetylene (C2H2), followed by ethylene (C2H4) [27–29]. A gaseous precursor occupies less space than a liquid or solid one, because they can be stored in certain specialized containers. Some precursors are produced as a by-product of industrial processes, such as biogas, which is constituted essentially of methane and carbon dioxide [15].

#### *3.2.2 Liquids*

Liquid carbon precursors are less commonly used in CVD methods. The most common precursors used in CVD are hexane (C6H14), ethanol (C2H5OH), and benzene (C6H6) [30–32]. These liquid carbon precursors are easy to use and relatively inexpensive compared with gaseous ones [15, 32].

In contrast to the use of gaseous materials, when the precursor used is in a liquid state, a previous stage is needed to transform the precursor from its liquid form to a vapor in order to be deposited on the metal substrate. Various CVD configurations have been used to work with liquid precursors. An approach constitutes the use of an external source of heat to vaporize liquids with high boiling points. Ultrasonic baths can be used to form aerosols from the liquids [15]. Unlike gaseous precursors that have a certain flow, an external constant gas flow is needed to carry the post-treatment precursor to the reaction chamber [15, 16]. Some of these precursors could be harmful to human health, since some may be volatile organic compounds or carcinogenic in nature [15].

#### *3.2.3 Solids*

Solid carbon precursors are equally rarely used. They are more complex in terms of chemical and biological structure. Any organic material that works as a carbon source can be used, including plant waste, plastics, animal waste, insect parts, even food. Therefore, solid precursors occupy more space in the reaction chamber than gaseous or liquid precursors [15, 33].

As with liquid precursors, prior to the synthesis process, an extra step is required to convert the solid material into a gas phase before acting on the metal catalyst. More energy is required to carry out the process, which can increase costs. Solid carbon precursors can be placed directly on top of the catalyst metal so that graphene forms on the back of the catalyst. Polymers have been spin coated directly on copper foils and used as carbon precursor [34]. Most of the precursors used are solid wastes or biomass; using these products to form graphene would positively impact waste

recycling for the production of a high-value product and may reduce the overall cost of synthesis [15].

**Table 1** presents different carbon precursors that have been used for the synthesis of graphene, divided by their previously discussed physical states, along with a detailed example of the synthesis process using one of those precursors.

#### **Table 1.**

*Carbon precursors used for the synthesis of graphene organized by their physical state. An example of the synthesis performed is shown in each case.*