Effect of hybridization on the value-added activated carbon materials

Int J Ind Chem (2016) 7:249–264 DOI 10.1007/s40090-016-0089-5 REVIEW Effect of hybridization on the value-added activated carbon materials Samira Bagheri1 • Nurhidayatullaili Muhd Julkapli1 Received: 30 June 2015 / Accepted: 8 June 2016 / Published online: 16 June 2016 Ó The Author(s) 2016. This article is published with open access at Springerlink.com Abstract This paper provides a concise review of recent advances in activated carbon (AC) and its corresponding modified material. Topics covered in this work include the synthesis and characterization of AC as the feedstock materials, as well as the properties and applications of the subsequent hybrid material for different industries. Numerous research studies have since reported remarkable physical, chemical, thermal, conductivity, porosity, and mechanical (stiffness and strength) properties of AC in different types of multiple material matrices, including polymers, metals, and ceramics. The incorporation of AC particles into material matrices may result in the formation of an entire new class of advanced materials, due to the resulting strong interfacial bonds of the hybrid components. Although this requirement is no different from those that offer conventional hybrid materials, the scale of the reinforcement and filled phase of the AC has changed from micrometers to nanometers. This create opportunities to increase the potential applications of AC hybrid materials of the development of fundamentally unique new materials for in chemical conversion, environmental, and fuel storage applications. Keywords Nanotechnology
Biomass
Hybrid
Interfacial
Green & Nurhidayatullaili Muhd Julkapli 1 Nanotechnology and Catalysis Research Centre (NANOCAT), University Malaya, IPS Building, 50603 Kuala Lumpur, Malaysia Introduction: carbon-based materials Both nanomaterials and carbon materials are attracting quite a bit of attention within the scope of material science and technology [1–4]. Carbon materials at the nanoscale level, named nanocarbon materials, not only exhibit better properties compared to those of conventional or microscale materials, but also possess new characteristics that conventional materials lack [2, 3]. Recent studies show proved that nanocarbon materials can be used as medical materials, electronic materials and environmental protection materials, all of which are revolutionary materials of the twenty-first century [5]. Activated carbon: advantages Activated carbon (AC), which is a nanocarbon possessing a sponge-like structure, is made up of small chemically bonded heteroatoms, chiefly oxygen and hydrogen [6–9]. The manufacture of AC mirrors is similar to that of a highly fractal material; both are uniformly formed, with each magnification having tailored pore widths and with pores having an adjustable width [8]. Generally, there are many physical forms of ACs; some examples include granular AC, powdered AC, AC fibers, and AC cloths (Table 1). In synthesizing AC, nearly any carbonbased materials are applicable as precursors [9]. In practice, this includes nutshells and fruit stones, charcoal, wood, peat, soft coal, lignite, petroleum coke, and bituminous coal, among others [8]. Taking into consideration that these materials are high in carbon content and low in inorganic content and composed of a high proportion of carbon and low amount of inorganic components, it makes them suitable for the synthesis of ACs (Fig. 1). 123 250 Int J Ind Chem (2016) 7:249–264 Table 1 Preparation of different physical forms of AC AC categories Preparation methods Characteristics References Granular AC Prepared from hard material such as coconut shells and includes particles retained in a 0.177 mm mesh sieve Column filler for liquid and gas treatments [10] Powdered AC Obtained in particles less than 0.1777 mm Because of its small particles, the adsorption is normally very effective; however, settling and removal tend to be slower [11] AC fibers Prepared from the homogenous polymeric raw material Indicates a monodispersed pore size distribution [12] Developed by using a precursor phenolic or viscose rayon Well thought out to be good adsorbents because of its low pressure drop during the process, flexibility and high contact efficiency AC cloth Usually mixed with the liquid to be treated and disposed afterward Can be regenerated after utilizing Its thin fiber shape enhances intraparticle adsorption and contact efficiencies between the aqueous media [13] agglomerate with high specific surface areas and pore volumes, even when lacking microporosity. Pores in the mesoporous range and low tortuosity are formed due to the network-like assembly of AC aggregation, encouraging mass transfer [13]. This is mainly favorable for quick reactions and limited diffusion applications, such as liquid phase uses. Activated carbon: synthesis and properties Fig. 1 The selection criteria of raw material for AC production Furthermore, the heterogeneous surface of AC provides it with extra positive values [9]. The heterogeneous surface property of AC came from two foundations; chemical and geometrical. Geometrical heterogeneity is mainly due to the variation of shape and size of pores, cracks, steps, and pits [10, 11]. Chemical heterogeneity is not only related to different functional groups, chiefly oxygen groups often positioned at the turbostratic crystallites’ edges, but also relevant to several surface impurities [12]. Both kinds of heterogeneity result in exceptional absorption properties of ACs. The porous structure of ACs is controlled by the precursor used in the manufacturing process, the activation technique utilized, and the activation amounts [13]. Therefore, AC characterization techniques greatly influence the adsorption rate and capacity. Subsequently, AC was characterized for high carbon proportion, great surface areas, abundant micropores, and narrow or small aperture having the advantage of fast adsorption rate, large adsorption capacity, and simpler regeneration in the gas– liquid adsorption fields [10]. Other leading benefits of AC are its high purity, which prevents poisoning/side reaction, the chemical stability in basic/acidic media, and excellent mechanical performance [12]. Moreover, AC tends to 123 Generally, the AC manufacturing process starts with the carbonization of natural or synthetic precursors at a temperature range of 600–1000 °C, and an activation step at a higher temperature by CO2 or steam is done afterward [14, 15]. Another method requires chemical activation using alkalis, such as Na2CO3, K2CO3, NaOH, and KOH, and alkali earth metal salts, such as ZnCl2 and AlCl3, and certain acids (H3PO4 and H2SO4) [16–18]. The aforementioned chemicals are dehydrating agents, which greatly affect the pyrolytic decomposition and inhibit the formation of tar. Thus, the synthesis and characterization of AC reported in many studies indicated that its porosity depends on the activation setti (...truncated)