Scientists have found a method to mimic nature’s own process of reducing carbon dioxide in the atmosphere, namely photosynthesis, to capture excess carbon dioxide in the atmosphere.

Artificial Photosynthesis

• Artificial photosynthesis (AP) is a chemical process that mimics the natural process of photosynthesis to convert sunlight, water, and carbon dioxide into carbohydrates and oxygen.
• The term artificial photosynthesis is commonly used to refer to any scheme for capturing and storing the energy from sunlight in the chemical bonds of fuel (a solar fuel).
• Photocatalytic water splitting converts water into hydrogen and oxygen and is a major research topic of artificial photosynthesis.
• Light-driven carbon dioxide reduction is another process studied that replicates natural carbon fixation.

Try this PYQ:

Which of the following adds/add carbon dioxide to the carbon cycle on the planet Earth?

1. Volcanic action
2. Respiration
3. Photosynthesis
4. Decay of organic matter

Select the correct answer using the code given below:

(a) 1 and 3 only

(b) 2 only

(c) 1, 2 and 4 only

(d) 1, 2, 3 and 4

Challenges in AP

• Research on this topic includes the engineering of enzymes and photoautotrophic microorganisms for microbial biofuel and biohydrogen production from sunlight.
• This AP harnesses solar energy and converts the captured carbon dioxide to carbon monoxide (CO), which can be used as a fuel for internal combustion engines.
• In AP, scientists are essentially conducting the same fundamental process in natural photosynthesis but with simpler nanostructures.
• However, there are plenty of hurdles to overcome as a successful catalyst to carry out AP.

What have Indian researchers achieved?

• Indian researchers have designed and fabricated an integrated catalytic system based on a metal-organic framework (MOF-808) comprising of a photosensitizer that can harness solar power and a catalytic centre that can eventually reduce CO2.
• A photosensitizer is a molecule that absorbs light and transfers the electron from the incident light into another nearby molecule.
• The scientists have immobilized a photosensitizer, which is a chemical called ruthenium bipyridyl complex ([Ru (bpy)2Cl2]) and a catalytic part which is another chemical called rhenium carbonyl complex ([Re(CO)5Cl]).
• They have fabricated it inside the nano space of a metal-organic framework for artificial photosynthesis.

Outcomes of the research

• The developed catalyst exhibited excellent visible-light-driven CO2 reduction to CO with more than 99% selectivity.
• The catalyst also oxidizes water to produce oxygen (O2).
• The Photocatalytic assembly, when assessed for CO2 reduction under direct sunlight in a water medium without any additives, showed superior performance of CO production.
• Being heterogeneous, the integrated catalytic assembly can be reused for several catalytic cycles without losing its activity.

Back2Basics:  Photosynthesis

• It is the process by which green plants and certain other organisms transform light energy into chemical energy.
• It is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism’s metabolic activities.
• This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis.

Get an IAS/IPS ranker as your 1: 1 personal mentor for UPSC 2024

Attend Now