Advantages And Disadvantages Of Photo-Catalysts And Pec Techniques For Solar Hydrogen Energy

The Hydrogen Fuel Cell could revolutionize the world. This ingenious technology, which creates electricity from the chemical reactions of hydrogen and oxygen has, in its 150-year history, passed many of the critical tests along the path from invention to innovation. Recent developments in fuel cell technology and concurrent developments within the energy and automotive industries have brought the world to brink of the fuel cell age and the hydrogen economy.

The process of photosynthesis, by which light energy is used to convert inorganic compounds into organic substances with the release of oxygen, may be the most important biological event sustaining life (Keir et al. 2017). In the light-dependent reactions, the chloroplasts of a plant use the pigment chlorophyll to convert light energy into chemical energy. This energy is used to split water and produce oxygen (Eller et al. 2015). The energy is later used in the light independent reactions, where carbon dioxide (CO2) undergoes carbon fixation with the aid of enzyme rubisco, because it catalyses both carboxylation and oxygenation reactions and most of responses of photosynthesis to light, CO2, and temperature (John Evans 2013).

Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into high-energy sugars and oxygen.

Why: The overall objective of the experiment is to improve the way in which electricity is converted from solar energy, while also attempting to lower the expenses of the process. If this project is successful, then the hydrogen and oxygen molecules derived from the water can be used to generate fuel cells.

In the contexts of history and research, interest in heterogeneous photocatalysis can be traced back to many decades when Fujishima and Honda discovered in 1972 the photochemical splitting of water into hydrogen and oxygen in the presence of TiO2 From this time, extensive research, much of it published, has been carried out to produce hydrogen from water in oxidation reduction reactions using a variety of semiconductor catalyst materials. With respect to a semiconductor oxide such asWO3, photocatalytic reactions are initiated by the absorption of illumination with energy equal to or greater than the band gap of the semiconductor. This produces electron-hole (e−/h+) pairs as in Equation (1.14), Figure

Photocatalysis is one of the clean and renewable technologies, utilizes naturally enormous abundant, clean and safe solar power. The cheap solar energy harnessing is one of the most exciting features to gain significant attention toward photocatalysis direction. Titanium oxide-based photocatalyst has shown considerable interest since the discovery because of the excellent properties such as chemical and photostability, eco-friendly nature and high catalytic reactivity.2,3 TiO2 photocatalysts have been widely engaged in various photocatalytic applications such as water and air cleaning, self-cleaning and anti-fogging TiO2 coated glasses, tiles, and shelters. TiO2 only generates electron-hole pairs under UV light, which are responsible for the photocatalytic reaction. There are numerous investigations have been done to alter the TiO2 structures to absorb visible lights. The strategy includes adding noble metals4, cations5, non-metals6, and metal oxides7 through various methods such as sol-gel8, physical ion-implantation methods,

It derives energy from spinning water turbines. Hydroelectric power is a low-cost, renewable, air pollution-free energy source. Unfortunately there is not much room for this source left in the US and building large dams, flooding valuable river valleys, and eliminating free-flowing rivers are the negative externalities of this alternative. Electrolysis of water could be used to convert biomass (plants or plant-based materials) into methane or electricity to generate hydrogen gas. Current technology with little improvement could lead to these fuels being used more abundantly. Moreover, the storage, use, and transportation of these fuels would be

Even though hydrogen as a fuel seems to answer every problem we want it to; it also has setbacks. Although we have the technology now to bring us an endless supply of hydrogen fuel we do not have the storage or infrastructure capabilities for it. “Hydrogen

In addition to the applications mentioned already, they can be utilized in a number of treatment strategies. For example, photocatalysis can be used for water disinfection to destroy humic substances, viruses and bacteria and even toxic chlorinated compounds. Heavy metals like Hg, Cr, Pb, Cd, As and Ni are removed from water using photocatalysis. Photodynamic therapy is another novelty in the field of photocatalysis. Radicals generated by illumination of light on TiO2 target cancer cells and destroy them2. It should be stated that further investigation is necessary in order to overcome some of the issues related to this

This reduces the energy barrier as it bends the linear CO2 molecule which increases its reactivity. The photocatalytic reduction of CO2 involves the breaking of C-O bonds and formation of C-H bonds. The product is dependent on the reducing agent, charge carriers and experimental conditions5. Photocatalysis is particularly advantageous over traditional thermal activation as the process requires lower temperatures and pressures. Additionally, the catalysts are typically formed photochemically in one step the leading to a higher

Scientists have also figured out how to harness solar energy, using electricity from photovoltaic cells to yield hydrogen that can be later used in fuel cells. But hydrogen has failed to catch on as a practical fuel for cars or for power generation in a world designed around liquid fuels.

In 2012, researcher Daniel Nocera released his long-awaited invention, the “artificial leaf”: a small solar device capable of converting sunlight and water into hydrogen for the purpose of providing a new form of alternative energy. However, Nocera’s invention came with a very large flaw upon its release: at the time, there was no competent means by which to use hydrogen as a source of fuel, as nearly all pre-existing fuel infrastructure is built upon the concept of liquid fuels. A solution came about only three years later, when Nocera partnered with Harvard chemists to pioneer a genetically-modified bacterium capable of quickly converting hydrogen into an alcohol-based liquid fuel with the potential for use in gas stations and cars. This development also solves another issue in Nocera’s original artificial leaf design, the lack of potential for storable fuel, through the conversion of the hydrogen gas to the liquid fuel.

Life on Earth is dependent entirely on the energy from the Sun, not only to keep the planet at a suitable temperature but also to provide the energy required to sustain life. The energy of the Sun, in the form of photons, is actively captured by chlorophyll and related pigments present in photosynthetic organisms, like plants and algae. This captured energy is used to convert carbon dioxide into complex energy-rich molecules that can be used by themselves

The process of photosynthesis is a convoluted one; which relies on the carbon dioxide, water, and the sun’s light energy. The first stage of photosynthesis, is known as the light-dependent reaction. This occurs in the thylakoid membrane as the light photons are captured and excited electrons are bounced around inside the thylakoid compartment until it is captured in the photosystem. The electrons are then sent through an electron transfer chain to the next photosystem. In order to replace lost electrons, photosystem II pulls more electrons off water molecules. This reaction produces hydrogen ions along with oxygen. The hydrogen ions are propelled through ATP synthases to attach to ADP, therefore ATP forms. The next photosystem absorbs the electrons that go through the first electron transfer chain, and it also absorbs light energy to create another electron transfer chain. At the end of this chain, a coenzyme NADP+ accepts the electron along with a hydrogen ion, which creates NADPH.

Index terms: Introduction, working, why only Hydrogen element, comparison with Batteries, cost analysis, advantages and disadvantages, applications, problems faced in Hydrofuel cells, conclusion.