**3.1 Environmental applications of nanocarbon-polymer-based composites**

Ecological balance is essential which is majorly affected by different pollutants. Therefore, it is difficult to check ecology balance simultaneously with the rapid growth of industrialization and civilization. In this regard, it is required to increase effectiveness by taking some corrective measures in pre-existing methods of controlling pollutions [65, 66]. In light of nanotechnology knowledge, advanced nanomaterial/composite materials can be developed that significantly enhanced the performance of different pre-existing treatment technologies [55, 57]. For example nanocarbon provide high specific surface area thus, carbon-based nanomaterial/ composites provide high specific surface for the adsorption process [29, 30] oxidation process [67, 68], and electrochemical applications [69, 70]. Although, the

**7**

*Recent Developments in Nanocarbon-Polymer Composites for Environmental and Energy…*

nanocarbon is one of the most effective adsorbents used in the wastewater treatment because of its high surface area to weight ratio. But, it cannot be applied directly in flow or dynamics conditions [71]. Specific affinity of metal functionalizednanocarbon based materials as adsorbent exhibited high adsorption capacity specific for different heavy metals (As, Fe, Pb, Cu), vitamin B12, nitrates, phosphates and show superior antibacterial activity than that of primitive activated carbon [72–77]. Moreover, after adsorption operation, specific adsorbate with nanocarbon based adsorbent can be separated by the mechanism of filtration and can be recycled [10]. But, high preparation cost of nanocarbon based materials and uncertainties regarding the leaching potential are the major challenges in the application of nanocarbon based materials. Silver coated carbon-based nanomaterials can be used as an antibacterial material and used in disinfection purposes, antimicrobial activity and preparation of biomedical devices [78]. Carbon nanotubes, activated with alcohol 1-octadecanol can also be used as better adsorbent for the absorption of microwaves because of its antibacterial characteristics. So, it can be used in the water purifica-

Moreover, nanocarbons are not only important in the pollution reduction in different ecological sections, but it has significant importance in the monitoring of pollution stages. Carbon-based nanomaterials and their composites can be used for the development of different and efficient sensors (biochemical) to detect very low concentrations of chemical compounds in different environments. For example, carbon nanotubes loaded with ZnO nanoparticles can be used for congo red dye reduction from aqueous solutions and showing that ZnO/MWCNTs is a promising, environmentally friendly and efficient adsorbent for wastewater treatment [80].

Economy of any country is directly boom if they can produce and store energy particularly from renewable resource. In this viewpoint carbon-based nanomaterials and their composites can play an important role in the area of energy harvesting and energy storage. It is well known most of the nanocarbon composed of sp2 hybridization and possessed excellent properties such as, high pore size distribution, high surface area, with enhanced mechanical properties and improved electrical properties. In recent years, nanocarbon and nanocomposites are widely applied for developing energy storage and energy saving devices/instrument. Photovoltaic cells are commonly known as solar cell used as an alternative device for harvest renewable energy sources. Photovoltaic cells can be classified in two categories such as, thin films and crystalline silicon photovoltaic cells. Earlier, silicon, cadmium, copper-based compounds are used in the semiconductors used [81, 82] applied in energy storage devices. Nowadays thin-film group photovoltaic cells used platinumbased semiconductor for high band width/specific related applications. But, high cost and availability of platinum increases overall cost of an instrument. In this case carbon-based nanomaterials/composites can play an alternative role of platinumbased materials due to its superior properties [83]. Generally, nanomaterials prepared from graphene are used to enhance electron carriage and boost the efficiency of solar energy conversion [84]. Graphene-based materials can also be used in fuel

Supercapacitors are used for energy storage devices applied in electric vehicles, hybrid electric vehicles, backup power cells, and portable electronic devices due to its advanced properties such as, high-power density, very short charging time, and high cycling stability. The main mechanism of storage of energy in super capacitors are pseudo capacitance and electrochemical double-layer capacitance. In pseudo capacitor, faradic reactions mechanism is responsible for charge transfer processes.

**3.2 Energy applications of nanocarbon-polymer-based composites**

cells and batteries due to its favorable properties.

*DOI: http://dx.doi.org/10.5772/intechopen.85626*

tion technologies [79].

### *Recent Developments in Nanocarbon-Polymer Composites for Environmental and Energy… DOI: http://dx.doi.org/10.5772/intechopen.85626*

nanocarbon is one of the most effective adsorbents used in the wastewater treatment because of its high surface area to weight ratio. But, it cannot be applied directly in flow or dynamics conditions [71]. Specific affinity of metal functionalizednanocarbon based materials as adsorbent exhibited high adsorption capacity specific for different heavy metals (As, Fe, Pb, Cu), vitamin B12, nitrates, phosphates and show superior antibacterial activity than that of primitive activated carbon [72–77]. Moreover, after adsorption operation, specific adsorbate with nanocarbon based adsorbent can be separated by the mechanism of filtration and can be recycled [10]. But, high preparation cost of nanocarbon based materials and uncertainties regarding the leaching potential are the major challenges in the application of nanocarbon based materials. Silver coated carbon-based nanomaterials can be used as an antibacterial material and used in disinfection purposes, antimicrobial activity and preparation of biomedical devices [78]. Carbon nanotubes, activated with alcohol 1-octadecanol can also be used as better adsorbent for the absorption of microwaves because of its antibacterial characteristics. So, it can be used in the water purification technologies [79].

Moreover, nanocarbons are not only important in the pollution reduction in different ecological sections, but it has significant importance in the monitoring of pollution stages. Carbon-based nanomaterials and their composites can be used for the development of different and efficient sensors (biochemical) to detect very low concentrations of chemical compounds in different environments. For example, carbon nanotubes loaded with ZnO nanoparticles can be used for congo red dye reduction from aqueous solutions and showing that ZnO/MWCNTs is a promising, environmentally friendly and efficient adsorbent for wastewater treatment [80].
