China 
Africa 
Explore chapters and articles related to this topic
Carbon-Based Photocatalytic Nanomaterials for Clean Fuel Production
Published in Swamini Chopra, Kavita Pande, Vincent Shantha Kumar, Jitendra A. Sharma, Novel Applications of Carbon Based Nano-Materials, 2023
Saikumar Manchala, Jaison Jeevanandam
In view of the rapid rising of the world population and development of science and technology, people of developing countries are urging for better living standards which subsequently resulted in overusage of traditional energy sources (Tonda et al. 2017). Furthermore, it has led to the rise in the cost of energy and depletion in the availability of traditional fuels. The emission of hazardous pollutants during the combustion of these fuels is not only causing the greenhouse effect and climate change but is also affecting the health of living beings (Ulmer et al. 2019). In this regard, H2 is considered a clean fuel. So, the development of appropriate methods for the generation of H2 is necessary. Photocatalytic water splitting can mimic natural photosynthesis, which involves the conversion of sunlight energy into chemical energy in the form of H2 fuel, and it is an attractive avenue for clean energy generation and environmental safety (Chen et al. 2010, Wang et al. 2019b). Unfortunately, the performance of the presently developed photocatalysts does not meet the demands of large-scale practical applications. Therefore, the development of highly efficient visible light-active photocatalysts for renewable energy generation and environmental protection is still being sought.
Hydrogen Production by Catalytic Reforming Process
Published in Sonil Nanda, Prakash K. Sarangi, Biohydrogen, 2022
Chandramani Rai, Prabu Vairakannu
CO2 generation is zero, and thus this process can be eco-friendly. However, the electricity used in this process is generated by the combustion of coal or natural gas which produces CO2 (Fajrina and Tahir, 2019). Photocatalytic water splitting can be a better choice to produce hydrogen by using a renewable source of energy such as sunlight and water. The production of hydrogen by this process helps in reducing the global warming effect by lowering the CO2 production. In this process, water undergoes a redox reaction using a photo-catalyst, which can be chosen in such a way that it can be a good absorber of sunlight energy to produce a significant quantity of hydrogen. This process requires better interaction between catalyst, reactant, and light (Chouhan et al., 2016). The primary requirement of the photocatalytic process is light energy, which must be higher or equal than the bond energy gap of the semiconductor-based photo-catalyst (Acar et al., 2014). The thermolysis process is another method to produce hydrogen by water splitting using heat as an energy source. This process requires high temperatures (500–1000°C) to produce hydrogen (Muhich et al., 2015). Table 3.8 shows the comparison of hydrogen production through the water-splitting reaction. It can be noted that Au-N/TiO2 catalyst yielded the highest hydrogen evolution rate using a 300-watt power Xe-lamp.
Microfluidic photocatalysis
Published in Guangya Zhou, Chengkuo Lee, Optical MEMS, Nanophotonics, and Their Applications, 2017
The production of hydrogen by splitting water is a promising means to solving the future energy source crisis. However, it also faces some difficulties for practical applications. Photocatalytic water splitting utilizes sunlight and water as the sources for hydrogen production, which has been regarded as one of the important approaches and one of the cleanest energy sources. Although it is already an existing technology to produce solar fuel by using photovoltaic cells, direct synthesis of solar fuels by artificial photosynthesis has been found to be more scalable [42]. At least 1.23 V of energy is required to split water into hydrogen and oxygen, corresponding to a two-electron reaction. In this technique, one of the challenges is to develop an efficient photocatalyst that can absorb long wavelengths (particularly visible light), but still retain the ability to split water. There are many strategies to enhance the photocatalytic water splitting efficiency and the cut-off wavelength, such as doping with noble gas, plasmonic sensitization, impregnating a co-catalyst, loading a noble metal, and employing wire- or belt-shaped geometries.
Catalytic applications of phosphorene: Computational design and experimental performance assessment
Published in Critical Reviews in Environmental Science and Technology, 2023
Monika Nehra, Neeraj Dilbaghi, Rajesh Kumar, Sunita Srivastava, K. Tankeshwar, Ki-Hyun Kim, Sandeep Kumar
Photocatalytic water splitting refers to an artificial approach that includes three main components such as water, a photocatalyst, and sunlight for water splitting into its elemental ingredients (i.e. H2 and O2). Under sunlight, the electrons of semiconductor photocatalyst are excited from the valence band maximum (VBM) to conduction band maximum (CBM), forming electron-hole pairs which can participate in two water splitting reactions such as OER and HER. Therefore, the selection of a semiconductor photocatalyst is based on several factors like the small direct band gaps for absorption of broadband sunlight as well as high carrier mobility for efficient transport of charge carriers. The efficiency of the water splitting reactions can be increased with the selection of photocatalysts having band edge positions (of both VBM and CBM) closer to the redox potential of full water splitting reactions. Recently, 2D materials have been proposed as a potential candidate for photocatalytic water splitting reactions due to the availability of their large surface areas for light adsorption and further photocatalytic reactions (Ren et al., 2020).
Nanoscale hetero-interfaces for electrocatalytic and photocatalytic water splitting
Published in Science and Technology of Advanced Materials, 2022
Baopeng Yang, Dingzhong Luo, Shimiao Wu, Ning Zhang, Jinhua Ye
Because solar energy is an endless renewable energy source, photocatalytic water splitting is the most optimal way for producing H2. However, the low utilization of light energy during photocatalytic water splitting induces a low conversion efficiency and limits its large-scale development. In contrast to photocatalysis, electrocatalytic water splitting is a process that converts electrical energy directly into chemical energy, resulting in better conversion efficiency and higher-purity H2. Furthermore, electrical energy may be created affordably from renewable energy sources such as wind, solar, and tidal energy [60,61]. As a result, electrocatalytic water splitting is a more viable technique for converting renewable energy into hydrogen energy, and it has attracted the interest of researchers.
Metal nitride-based nanostructures for electrochemical and photocatalytic hydrogen production
Published in Science and Technology of Advanced Materials, 2022
Harpreet Singh Gujral, Gurwinder Singh, Arun V. Baskar, Xinwei Guan, Xun Geng, Abhay V. Kotkondawar, Sadhana Rayalu, Prashant Kumar, Ajay Karakoti, Ajayan Vinu
Fossil fuels–based energy generation is accompanied by greenhouse gas emissions, which is a major concern for global warming and climate change. The over-dependence on such resources and their continuous depletion creates the urgent demand for finding alternative solutions, which can provide a continuous and competent amount of energy as compared to conventional fossil fuels. Hydrogen is deemed to be one of the cleanest alternative sources of energy, which, however, is not readily available. Hydrogen is a highly effective source of energy and can deliver a very high mass-energy density of 120 MJ kg−1, which is close to five times the energy of fossil fuels such as coal [1]. Steam reforming is one of the major technologies for the industrial production of hydrogen. However, the accompanied emissions pose concerns for the environment [2,3]. Water, as the simplest of the molecules, contain 11.11 wt % of hydrogen, which along with its natural abundance makes it the pivotal theme of enormous research undertaken for hydrogen production by using either the electrochemical or the photocatalytic pathways [4,5]. These two methods of producing hydrogen are more sustainable as compared to the industrial steam reforming process for hydrogen generation as these methods are more sustainable and cause no damage to the environment. Although the electrochemical pathway to produce hydrogen via electrolysis of water is a well-established method on a commercial basis, photocatalytic water splitting stands out for more sustainable production of hydrogen from solar power, which is a renewable source of energy. A catalytic material is essential to drive the splitting of water and noble metals have been the preferential choice for this purpose owing to their high catalytic activity [6,7]. However, the primary drawbacks of employing noble metals are their high cost and low natural abundance [8]. Therefore, it is highly significant to develop non-noble metal electro- and photo-catalysts that are economical, available in large quantities, and highly efficient for producing hydrogen from water.