Splitting Molecules To Store Energy

Collectively, the world has been relatively reluctant to make a switch to green energy solutions. Still, in recent years, solar energy has been emerging as a leading source of renewable energy. In a post from a few months back, I designed a photovoltaic (PV) solar panel system for my own home, and I found that these systems are comparatively much more expensive than traditional nonrenewable energy systems. This is true across the board, like in large commercial or industrial applications of the technology. Additionally, the immediate question that comes to mind about solar panels, how they store enough energy at night, has set back their widespread implementation. Surely if a technology that was both cost and energy-efficient were revealed, it would genuinely transform the world! I looked into an article from Stanford Engineering summarizing groundbreaking research on a process called photoelectrochemical (PEC) water splitting.

Image Credit: https://en.wikipedia.org/wiki/Water_splitting#/media/File:Electrolysis_of_Water.png

This process would benefit the environment in many areas, such as potentially not emitting any greenhouse gasses (GHG). It has been known for years, but the challenge is scaling it up to be used in industrial settings. The Stanford engineers' research focused on this, growing the energy efficiency of PEC water splitting. According to the article, they "were able to capture and store 30 percent of the energy captured from sunlight into stored hydrogen, beating the prior record of 24.4 percent."

PEC water splitting involves utilizing sunlight energy to break water molecules down into their individual atoms of hydrogen and oxygen. The amount of energy produced and then stored from these bonds' breaking is a crucial factor. Catalysts used to facilitate this process have only been improving; the engineers at Stanford used new "water-splitting catalysts, in which electrons flow through the catalytic materials to break apart the stable H2O molecule." They allowed them to produce double the hydrogen and therefore have more energy stored.

Image Credit: https://onlinelibrary.wiley.com/doi/full/10.1002/adsu.201600035

The silicon solar cells making up standard PV panels drive their cost to be so high. PEC water splitting is also being developed in the form of a panel. The Stanford engineers used a new type of solar cell to achieve higher efficiency, called a triple junction cell, whose materials capture red, green, and blue light. Because the cells' materials can capture these different colors of light, their efficiency is much higher than the PV system, which only uses one junction. According to the article, the new cells "convert 39 percent of incoming solar energy into electricity, compared with roughly 20 percent for silicon-based, single-junction solar cells found on rooftops worldwide.

Image Credit: https://onlinelibrary.wiley.com/doi/10.1002/advs.201600337

Though the Stanford engineers' PEC water splitting process was highly effective, it required materials such as platinum that made it not viably scalable. However, cost-effective yet highly efficient materials and their placement are being closely researched to serve as catalysts for the process. Since Stanford's research in 2016, improvements to cost and efficiency have expanded. According to Shinshu University in Japan, in 2020, engineers have perfected catalysts "to engage in only desired reactions. This method made possible for the reaction to have no recombination losses." With such immense progress made by researchers in this area, the possibility that it will be scaled up and used in environmentally beneficial applications such as hydrogen-powered cars in the near future, is only improving. 

Image Credit: https://www.nature.com/articles/nmat4876




Sources: 

https://engineering.stanford.edu/magazine/article/can-splitting-water-become-efficient-way-store-solar-energy

https://www.energy.gov/eere/fuelcells/hydrogen-production-photoelectrochemical-water-splitting

https://www.sciencedaily.com/releases/2020/06/200603104547.htm#:~:text=Scientists%20have%20successfully%20split%20water,loss%20and%20undesired%20side%20reactions.

Comments

Post a Comment

Popular posts from this blog

Blue, Green, Gray, Pink, or Yellow Hydrogen: What it Means For Generating Cleaner Energy

Image
Hydrogen is the most abundant element on the planet; approximately 90 percent of all atoms are hydrogen. It is also the most simple element consisting of only one proton and neutron. Yet, hydrogen has the potential to be utilized as a source of generation and storage of clean energy. However, hydrogen does not often appear in nature on its own, so it requires a primary energy source to be produced. The sources and processes used to obtain hydrogen are often referred to by color, like grey, blue, green, yellow, and pink. Currently, grey hydrogen is the most common and economical method. Grey hydrogen is derived from natural gas by steam methane reforming (SMR). During SMR, natural gas is combined with hot steam, and the methane from natural gas reacts to form hydrogen and carbon monoxide. Extra water is added to convert the carbon monoxide to carbon dioxide while producing more hydrogen.  The key distinction between grey and blue hydrogen is that blue hydrogen aims for carbon dioxid...
Read more

Organic Photovoltaics: An Invisible Solar Energy Revolution in the Making

Image
Image: https://ensia.com/features/organic-solar-cells-energy-power/ Think solar energy. Your mind likely brings up images of fields or roofs dotted with blue rectangles – photovoltaic (PV) solar panels. But what if anything that basks in the sunshine could become an energy magnet? The technology making this possible could soon surround us – and we won’t even see it. PV panels have been springing up around the world for a while now, but this expansion poses some challenges. Their production requires huge amounts of (often fossil fuel-generated) energy and unsustainably sourced rare metals. Also, after they are decommissioned, high volumes of panel waste expose communities and the environment to the harmful substances found within them. On top of that, PVs are opaque and bulky, which limits where they can be installed. Meet Organic Photovoltaics (OPVs): the thin, flexible, and transparent up-and-comer ready to shake things up in the solar energy universe.  The sun emits virtuall...
Read more

Using Nanoparticles to Clean Ocean Oil Spills: Ferrofluids

Image
Marine oil spills have long-lasting devastating environmental consequences and dangerous conditions for workers. The US dumps 1.3 million gallons of oils into the ocean each year. These include the physical smothering of aquatic organisms, which leads to possible ecological changes, and toxic chemicals ending up in the water.  Currently, the most widely utilized method to clean these spills is chemical dispersants. They break down large areas of oil into tiny particles, similarly to dish soap; however, a problem with this is that, though, in smaller quantities, the oil becomes more scattered in the environment. While dispersants can break up the spill on the surface, the ocean's depths still end up polluted. Additionally, some chemicals found in dispersants may be more harmful than the oil itself. Another method involves using booms and skimmers. Booms are barriers placed around the spill that concentrate the oil into thicker layers. This allows vacuums or skimmers to capture, allo...
Read more