Firefly-like Water Splitting Cells Based on FRET Phenomena with Ultrahigh Performance over 12%

A firefly-like chemiluminescence reaction was utilized in a ZrO₂ nanoparticle matrix of water splitting cells, where the chlorophyll of <i>Lantana camara</i> was used as the major photosensitizer to excite electrons to the conduction band of ZrO₂. The fluorescence resonance energy transfer (FRET) was induced by rubrene, a firefly-like chemiluminescence molecule, and <i>Lantana camara</i> chlorophyll combined with 9,10-diphenylanthracene. The ZrO₂ nanoparticle film coated by the chlorophyll of <i>Lantana camara</i> and 9,10-diphenylanthracene under chemiluminescence irradiation in 1 M KHCO₃ water solution demonstrated the highest photocurrent density (88.1 A/m²) and the highest water splitting efficiency (12.77%)

High-Efficiency Water-Splitting Solar Cells with Low Diffusion Resistance Corresponding to Halochromic Pigments Interfacing with ZrO₂

ZrO₂ nanoparticle films coated with halochromic pigments are applied to water-splitting solar cells. On the basis of our results, ZrO₂ nanoparticle films coated with methyl orange have remarkable water-splitting properties. Under positive applied voltages and AM 1.5G irradiation, the highest hydrogen gas generation rate (1.8 mL/h·cm²) is measured for ZrO₂ nanoparticle films coated with methyl orange in 0.2 M H₂SO₄ water solution as electrolyte. As the electrolyte is changed from KHCO₃ water solution to the H₂SO₄ water solution, the interface resistance between ZrO₂ corresponding to halochromic pigments is reduced (from 107 to 11.7 Ω·m) and the electron diffusion coefficient is raised (821.67%)

Photonic Fano Resonance of Multishaped Cu₂O Nanoparticles on ZnO Nanowires Modulating Efficiency of Hydrogen Generation in Water Splitting Cell

The different-shape Cu₂O nanostructured in solar water splitting system serves as the photon absorber structure for modulating photoelectric conversion to challenge the issue of the high resistance and low electronic mobility with the different light trapping effect due to the orientation and geometry of Cu₂O. Finite difference time domain (FDTD) simulation results demonstrate that the Cu₂O nanostructured of truncated octahedral exhibits photonic Fano resonance compared with the other shapes. The generation rate of electrons and holes can rise with truncated octahedral Cu₂O nanostructures on the ZnO nanowires. By combining solar water splitting with photonic Fano resonance, we can use a lower voltage 0.7 V (the standard potential of the water electrolysis is −1.23 V) to splitting water, and then separate H₂ and O₂ into different electrodes. The hydrogen generation rate of truncated octahedral Cu₂O can reach 3 × 10^–4 ml/s·cm², which is about 10 times higher than that of Cu₂O in other shapes by modulating photonic Fano resonance, which has the potential application in the field of integrated quantum system in the future

Hydrogen Generation of Cu₂O Nanoparticles/MnO–MnO₂ Nanorods Heterojunction Supported on Sonochemical-Assisted Synthesized Few-Layer Graphene in Water-Splitting Photocathode

In this study, we investigated the production of hydrogen by photochemical water splitting. A multi-shaped Cu₂O nanoparticles/MnO–MnO₂ nanorods heterojunction on a few-layer graphene-based electrode serves as the photocathode. Multi-shaped Cu₂O nanoparticles, including truncated cubic shape, cuboctahedral shape, truncated octahedral shape, and octahedral shape, were then coated on square manganese nanorods on a few-layer graphene-based electrode as the photosensitizer. Finally, the efficiency of hydrogen production was measured and recorded. The Cu₂O nanoparticles/MnO–MnO₂ nanorods heterojunction generates photoelectrons to reduce hydrogen ions into hydrogen gas. The manganese dioxide nanorods were combined with cuprous oxide multi-shaped nanoparticles to be simultaneously utilized in hydrogen production as a photochemical water-splitting solar cell. The highest rate of hydrogen generation is 33.0 mL/min m² under solar simulation radiation. This study highlights the significance of a back electron–hole recombination loss and transportation process on the surface of a water-splitting photocathode, retarding the appearance of the photocurrent and requiring a greater amount of energy from a solar device