Defect and Donor Manipulated Highly Efficient Electron–Hole Separation in a 3D Nanoporous Schottky Heterojunction

Abstract

Given the rapid recombination of photogenerated charge carriers and photocorrosion, transition metal sulfide photocatalysts usually suffer from modest photocatalytic performance. Herein, S-vacancy-rich ZnIn2S4 (VS-ZIS) nanosheets are integrated on 3D bicontinuous nitrogen-doped nanoporous graphene (N-npG), forming 3D heterostructures with well-fitted geometric configuration (VS-ZIS/N-npG) for highly efficient photocatalytic hydrogen production. The VS-ZIS/N-npG presents ultrafast interfacial photogenerated electrons captured by the S vacancies in VS-ZIS and holes neutralization behaviors by the extra free electrons in N-npG during photocatalysis, which are demonstrated by in situ XPS, femtosecond transient absorption (fs-TA) spectroscopy, and transient-state surface photovoltage (TS-SPV) spectra. The simulated interfacial charge rearrangement behaviors from DFT calculations also verify the separation tendency of photogenerated charge carriers. Thus, the optimized VS-ZIS/N-npG 3D hierarchical heterojunction with 1.0 wt % N-npG exhibits a comparably high hydrogen generation rate of 4222.4 μmol g–1 h–1, which is 5.6-fold higher than the bare VS-ZIS and 12.7-fold higher than the ZIS without S vacancies. This work sheds light on the rational design of photogenerated carrier transfer paths to facilitate charge separation and provides further hints for the design of hierarchical heterostructure photocatalysts.

Short-Wave Infrared Light-Emitting Diodes Using Colloidal CuInS2 Quantum Dots with ZnI2 Dual-Passivation

“…64,65 Following the ZnI 2 IP treatment, the diameter significantly decreased, suggesting reduction in the resistance of the device. 64,66 These IS measurement results revealed that the ZnI 2 IP can reduce interfacial defects and trap states, 65 enhancing the electrical connectivity between CIS-ZnI 2 -QDs and ZMO ETL layers, consequently reducing the complex resistance of the overall LED devices.…”

“…Next, to investigate the impact of ZnI 2 IP at the QD-ETL interface, we conducted impedance spectroscopy (IS) measurements to assess the electrical connectivity of the two layers (i.e., CIS-QD and ETL layers) in the QLED devices (Figure G. As depicted in Figure G, the Nyquist plots for both the CIS-ZnI 2 -QLED and ZnI 2 -IP-treated CIS-ZnI 2 -QLED (denoted as CIS-ZnI 2 -IP-QLED) devices showed a semicircle shape, indicative of an RC circuit consisting of a resistor (R) and a capacitor (C) within the device. , Following the ZnI 2 IP treatment, the diameter significantly decreased, suggesting reduction in the resistance of the device. , These IS measurement results revealed that the ZnI 2 IP can reduce interfacial defects and trap states, enhancing the electrical connectivity between CIS-ZnI 2 -QDs and ZMO ETL layers, consequently reducing the complex resistance of the overall LED devices.…”

Synergistic Enhancement of Water-Splitting Performance Using MOF-Derived Ceria-Modified g-C3N4 Nanocomposites: Synthesis, Performance Evaluation, and Stability Prediction with Machine Learning

“…This study underscores the utilization of an ML approach in materials science research, and regarding this, the RNN-based LSTM model demonstrates effectiveness in predicting and forecasting the stability of photoanodes. Any observed decline in photoanode stability can likely be attributed to factors such as corrosion, material degradation, or surface passivation . Overall, the developed photoanodes exhibit robust stability over time, rendering them suitable for efficient PEC performance.…”

Triazinyl-graphdiyne induces electron directional migration to drive charge separation of CdS for photocatalytic hydrogen evolution

“…8(e)-(h)). 64 It was observed that the energy levels of C 1s and N 1s orbitals on the surface of CS/TA-10 moved towards low binding energy under light illumination, while the orbital energy levels of S 2p and Cd 3d orbitals moved towards high binding energy due to the formation of Schottky heterojunctions between CdS and TA-GDY. In the presence of light, the photoexcitation of CdS leads to the separation of photogenerated electrons from holes and the transfer of photogenerated electrons from the valence band to the conduction band.…”