am0c10279_si_001.pdf (1.68 MB)
Chlorophyll(a)/Carbon Quantum Dot Bio-Nanocomposite Activated Nano-Structured Silicon as an Efficient Photocathode for Photoelectrochemical Water Splitting
journal contribution
posted on 2020-08-07, 16:05 authored by Krishnendu Roy, Dibyendu Ghosh, K. Sarkar, Pooja Devi, Praveen KumarSolar-driven
water splitting is considered as a futuristic sustainable
way to generate hydrogen and chemical storage of solar energy. Further,
considering the technological competence, silicon is one of the potential
materials for developing large-scale and cost-effective photocathodes
(PCs), but it lacks efficacy and stability. Here, we show that chlorophyll(a)/carbon quantum dots (Chl/CQDs) bio-nanocomposite (b-NC)-decorated
Si-nanowires (SiNWs) as PC can surpass the reported efficiency for
photoelectrochemical (PEC) hydrogen generation along with stability.
The optimized heterojunction (Chl/CQDs_SiNW) significantly enhances
broad-band solar absorption and protects Si surface from corrosion.
Further, the appropriate band alignment enforces efficient photogenerated
charge separation and possesses directional exciton transport property
via the Förster resonance energy transfer (FRET) mechanism.
This synergic effect demonstrates an ∼18 times increase in
photocurrent density (26.36 mA/cm2) compared to pristine
SiNW PC at 1.07 V vs reversible hydrogen electrode (RHE). The efficiency
reaches ∼7.86%, which is comparably the highest reported for
hybrid Si-based photocathodes. Hydrogen evaluation rate was measured
to be ∼113 μmol/h at 0.8 V vs RHE under 1 sun illumination.
With Si-process line compatibility, this new finding opens a new direction
toward the development of Si-based efficient and stable PCs at a large
scale for commercial applications.
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- Biophysics
- Space Science
- Physical Sciences not elsewhere classified
- Genetics
- Molecular Biology
- Neuroscience
- Pharmacology
- Evolutionary Biology
- Environmental Sciences not elsewhere classified
- Chemical Sciences not elsewhere classified
- Ecology
- Biological Sciences not elsewhere classified
- Inorganic Chemistry
- Plant Biology
Keywords
Chlexciton transport propertystabilityhydrogen generationPhotoelectrochemical Water Splittin...Si surface1 sun illuminationefficiencychemical storageSiNW PCphotogenerated charge separationPEChydrogen electrodeoptimized heterojunctionSi-based photocathodesFRETsynergic effect1.07 V vsHydrogen evaluation rateSi-process line compatibilityEfficient Photocathodeband alignment0.8 V vs RHE
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