Opto-stimulation of semiconductor-biointerfaces provides efficient pathways towards eliciting neural activity through selective spectral excitation. In visual prosthesis, tri-colour stimulation capability is the key to restoring full-colour vision. Here we report on investigation of organic photoactive π-conjugated donor–acceptor small molecules based on triphenylamine whose absorption spectra are similar to those of the photoreceptors of the human eye. Photoactive device fabrication and characterisation towards full colour, pixelated retinal prosthesis based on inkjet printing of these molecules is demonstrated, with round pixels reaching 25 microns in diameter. Photo-response is studied via interfacing with biological electrolyte solution and using long-pulse, narrow-band excitation. Both photo-voltage and photo-current responses in the devices with a ZnO hole-blocking interlayer show clear signatures of capacitive charging at the electrolyte/device interface, also demonstrating spectral selectivity comparable to that of human eye’ cones and rods.
Overall water splitting using a photocatalyst absorbing a wide range of visible light is an ideal means of producing renewable hydrogen, and Nb-based oxynitrides are potential candidates for this purpose due to their narrow band gaps. However, it is challenging to prepare such materials as efficient photocatalysts because Nb⁵⁺ species are readily reduced during synthesis, and the energy offsets between the band edges of such materials and the water redox potentials are small. In this study, a series of LaMgₓNb₁₋ₓO₁₊₃ₓN₂₋₃ₓ solid solutions (0.0 ≤ x ≤ 0.5) was synthesized in an attempt to modify the band structures and improve the water splitting activity of these compounds. The substitution of Mg²⁺ enlarged the band gap of LaNbON₂, shifting the conduction and valence band edges negatively and positively, respectively, while retaining visible light absorption up to 600 nm and beyond. Moreover, the concentrations of reduced Nb species at the oxynitride surfaces generated during nitridation were significantly decreased with increasing Mg²⁺ content. As a result, increasing the amount of Mg²⁺ in these materials enhanced their photocatalytic H₂ evolution activity. Moreover, the co-loading of RhCrOy and CoOz as cocatalysts for water reduction and oxidation, respectively, allowed LaMgₓNb₁₋ₓO₁₊₃ₓN₂₋₃ₓ (0.2 ≤ x ≤ 0.5) to simultaneously evolve gaseous H₂ and O₂ from water under visible light (λ > 420 nm). These observations demonstrate the effectiveness of this band engineering technique and the necessity for further refinements of material properties and surface modifications to realize visible-light-driven overall water splitting over Nb-based oxynitrides.
A shape-memory monolith has been used as a new emerging class of foldable nitrogen-fixing electrocatalysts, which shows remarkable activities both with and without electrode deformations.
PDI-TTMSS exhibits peculiar monotropic phase transition behaviors originated from flexible siloxane substituents.
NaNbO3-based (NN) energy storage ceramics exhibit high breakdown electric field strength (Eb) with large recoverable energy storage density (Wrec).
The oxygen vacancy containing Li-rich cathode Li1.2Ni0.13Co0.13Mn0.54O2−δ showed excellent energy density retention.
We fabricate carbon quantum dot-modified Na3V2(PO4)2F3hierarchical microspheres, which exhibit outstanding high-rate and ultralong-life performance as a half-cell cathode. A Na-ion full-cell (with a hard carbon anode) delivers high cell voltage and good cycling stability.
We report an innovative CO2/H2 fuel cell that can convert CO2 into CH4 while generating electricity instead of consuming it.
GDC nanoparticles reduce the reaction resistance associated with three-phase boundaries and improve oxygen transport in the Ni–YSZ electrode, as measured by electrochemical impedance spectroscopy under actual solid oxide cell operating conditions.
BaFe0.125Co0.125Zr0.75O3−δ perovskite is a novel and efficient MIEC electrode for IT-SOFCs. Symmetrical cells with an area-specific resistance of 0.13 Ω cm2 at 700 °C and 0.05 Ω cm2 at 800 °C have been prepared.
We report a facile synthetic protocol from aqueous solution for Na3SbS4-Na2WS4 superionic conductors with sodium-ion conductivity of 4.28 mS cm−1 at 25 °C, which is the highest one in reported sulfide electrolytes prepared via liquid-phase methods.
Three-dimensional (3D) fractal structure of Au–Bi2O3 is fabricated and shows excellent multifunctional performance towards CO2 reduction and optical gas sensing.
Limited oxygen surface exchange for oxygen transport membrane (OTM) material in humid atmosphere, correlated with Sr surface segregation identified using isotopic exchange and mass spectrometry.
The novel PDI complex can be self-assembled into a helical supramolecular structure. Moreover, the solution of the complex can also realize the visual detection of ATP.
Low oxygen annealing following anodization is a surprisingly effective method of defect engineering and optimizing α-Fe2O3 electrodes for a maximized photoelectrochemical (PEC) water splitting performance.
It is attractive to convert CO2 greenhouse gas into valuable compounds via photocatalysis with solar energy.
Reversible gas capture and release controlled by ferroelectric switching.
A dual-phase MoS2 with expanded interlayer distance is fabricated for sodium storage. The dual-phase MoS2 shows significantly improved electrical conductivity and enhanced Na+ diffusivity compared to the common 2H-MoS2.
Efficient CuBi2O4 based photocathode with large onset potential (1.1 VSHE) and high photocurrent density (1.87 mA cm−2 at 0.6 VSHE) has been fabricated for constructing the unbiased water splitting system with the suitable photoanode.
Using liquid crystalline triblock copolymer complexes with hydrogen-bonded azobenzene moieties, photopatterned colorless birefringent films were prepared by irradiation with linearly polarized light and subsequent extracting azobenzene moieties.
