A concern usually addressed in catalyst design is efficiency, in particular how much of the incident light can be used in a system in practice. This is comparable with , where light-to-chemical-energy conversion is measured. Photosynthetic organisms are able to collect about 50% of incident solar radiation, however the theoretical limit of photosynthetic efficiency is 4.6 and 6.0% for C3 and C4 plants respectively. In reality, the efficiency of photosynthesis is much lower and is usually below 1%, with some exceptions such as in tropical climate. In contrast, the highest reported efficiency for artificial photosynthesis lab prototypes is 22.4%. However, plants are efficient in using CO2 at atmospheric concentrations, something that artificial catalysts still cannot perform.
In addition to their universal occurrence in photosynthetic organisms, carotenoid pigments are important components of biomimetic photosynthetic constructs. Much of the photophysics and photochemistry including singlet energy transfer, triplet energy transfer, sequential electron transfer, radical pair recombination, spin states and spin dynamics observed in natural photosynthetic reaction centers and antennas can be mimicked by these constructs. In addition to playing a role in biomimetic energy and electron transfer processes, carotenoid pigments are essential components of artificial photosynthetic membranes where they participate in a redox-loop-based light-driven proton pump.
several biomimetic approaches to artificial ..
Oxidoreductases are promising catalysts for organic synthesis. To sustain their catalytic cycles they require efficient supply with redox equivalents. Today classical biomimetic approaches utilizing natural electron supply chains prevail but artificial regeneration approaches bear the promise of simpler and more robust reaction schemes. Utilizing visible light can accelerate such artificial electron transport chains and even enable thermodynamically unfeasible reactions such as the use of water as reductant.
Exponential technologies on the horizon | Deloitte Insights
Using approaches, artificial photosynthesis tries to construct systems doing the same type of processes. Ideally, a assembly could oxidize water with one catalyst, reduce protons with another and have a molecule to power the whole system. One of the simplest designs is where the photosensitizer is linked in tandem between a water oxidation catalyst and a hydrogen evolving catalyst:
PROBIST | Barcelona Institute of Science and Technology – …
As part of current research efforts artificial photonic antenna systems are being studied to determine efficient and sustainable ways to collect light for artificial photosynthesis. Gion Calzaferri (2009) describes one such antenna that uses zeolite L as a host for organic dyes, to mimic plant's light collecting systems. The antenna is fabricated by inserting dye molecules into the channels of zeolite L. The insertion process, which takes place under vacuum and at high temperature conditions, is made possible by the cooperative vibrational motion of the zeolite framework and of the dye molecules. The resulting material may be interfaced to an external device via a stopcock intermediate.
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Using biomimetic approaches, artificial photosynthesis tries to construct systems doing the same type of processes. Ideally, a triad assembly could oxidize water with one , reduce protons with another and have a photosensitizer molecule to power the whole system. One of the simplest designs is where the photosensitizer is linked in tandem between a water oxidation catalyst and a hydrogen evolving catalyst: