Designing In2S3/FeVO4/CNT Photoelectrode for Enhanced Visible Light Driven Oxygen Evolution

The development of efficient and stable photoelectrodes is essential for the advancement of photoelectrochemical (PEC) water-splitting technologies, which hold promise for efficient oxygen evolution reaction (OER), necessary for sustainable hydrogen production. In this study, the synthesis of a ternary composite, In2 ${_2 }$ S3 ${_3 }$ /FeVO4 ${_4 }$ /CNT has been reported, designed for highly efficient PEC oxygen evolution. The formation of In2 ${_2 }$ S3 ${_3 }$ /FeVO4 ${_4 }$ heterostructure enhances PEC performance significantly due to the type-II band alignment, which minimizes electron-hole recombination and improves charge separation. The addition of CNTs further enhances performance by providing conductive pathways that improve electron transport and reduce charge transfer resistance. The resulting In2 ${_2 }$ S3 ${_3 }$ /FeVO4 ${_4 }$ /CNT ternary composite achieves a current density of 14.70 mAcm- 2 ${^{ - 2} }$ at 1.8 V vs. RHE, representing a notable increase in performance. Electrochemical impedance spectroscopy (EIS) shows that the ternary composite has the lowest charge transfer resistance, while Bode phase analysis indicates a longer carrier lifetime, emphasizing the synergistic effect of heterostructure formation and CNT inclusion. The ternary composite also demonstrates excellent stability and responsiveness during transient photocurrent cycling, maintaining performance under repeated chronoamperometric ON/OFF cycles, making it a strong candidate for water-splitting applications driven by visible light.

The paradox of thermal vs. non-thermal effects in plasmonic photocatalysis

The debate surrounding the roles of thermal and non-thermal pathways in plasmonic catalysis has captured the attention of researchers and sparked vibrant discussions within the scientific community. In this review, we embark on a thorough exploration of this intriguing discourse, starting from fundamental principles and culminating in a detailed understanding of the divergent viewpoints. We probe into the core of the debate by elucidating the behavior of excited charge carriers in illuminated plasmonic nanostructures, which serves as the foundation for the two opposing schools of thought. We present the key arguments and evidence put forth by proponents of both the non-thermal and thermal pathways, providing a perspective on their respective positions. Beyond the theoretical divide, we discussed the evolving methodologies used to unravel these mechanisms. We discuss the use of Arrhenius equations and their variations, shedding light on the ensuing debates about their applicability. Our review emphasizes the significance of localized surface plasmon resonance (LSPR), investigating its role in collective charge oscillations and the decay dynamics that influence catalytic processes. We also talked about the nuances of activation energy, exploring its relationship with the nonlinearity of temperature and light intensity dependence on reaction rates. Additionally, we address the intricacies of catalyst surface temperature measurements and their implications in understanding light-triggered reaction dynamics. The review further discusses wavelength-dependent reaction rates, kinetic isotope effects, and competitive electron transfer reactions, offering an all-inclusive view of the field. This review not only maps the current landscape of plasmonic photocatalysis but also facilitates future explorations and innovations to unlock the full potential of plasmon-mediated catalysis, where synergistic approaches could lead to different vistas in chemical transformations.

Enhanced photoelectrochemical performance of NiS-modified TiO2 nanorods with a surface charge accumulation facet

Photoelectrochemical (PEC) water splitting for hydrogen production technology is considered as one of the most promising solutions to energy shortage and environmental remediation. TiO2/NiS nanorod arrays were successfully prepared using hydrothermal deposition followed by the successive ionic layer adsorption and reaction (SILAR) method. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and photoluminescence (PL) spectra characterization studies indicate the successful deposition of NiS on TiO2 NRs. The NiS deposition on TiO2 was optimized by controlling the impregnation cycle. The optimal sample exhibits a photocurrent density of 1.16 mA cm-2 at 0.6 V vs. Ag/AgCl, which is a 1.9-fold enhancement over that of pristine TiO2 nanorod arrays. The enhanced photoelectrochemical performance can be attributed to two aspects. On the one hand, the (101) crystal plane of rutile TiO2 is the facet where photogenerated holes accumulate and is an efficient active plane for the oxygen evolution reaction; on the other hand, NiS is a narrow band gap semiconductor, and its deposition on TiO2 nanorods can further promote the separation and transport of photogenerated charge carriers.

Recent Progress on Carbon Quantum Dots Based Photocatalysis

As a novel carbon allotrope, carbon quantum dots (CQDs) have been investigated in various fields, including photocatalysis, bioimaging, optoelectronics, energy and photovoltaic devices, biosensing, and drug delivery owing to their unique optical and electronic properties. In particular, CQDs' excellent sunlight harvesting ability, tunable photoluminescence (PL), up-conversion photoluminescence (UCPL), and efficient photo-excited electron transfer have enabled their applications in photocatalysis. This work focuses on the recent progress on CQDs-related materials' synthesis, properties, and applications in photocatalysis.