Nanoscale Janus Z-Scheme Heterojunction for Boosting Artificial Photosynthesis

CRISPR/Cas13a-Programmed Cu NCs and Z-Scheme T-COF/Ag2S for Photoelectrochemical Biosensing of circRNA

Circular RNAs (circRNAs), as a class of noncoding RNA molecules with a circular structure exhibit high stability and spatiotemporal-specific expression, making them ideal cancer biomarkers for liquid biopsy. Herein, a new photoelectrochemical (PEC) biosensor for a highly sensitive circRNA assay in the whole blood of lung cancer patients was designed based on CRISPR/Cas13a-programmed Cu nanoclusters (Cu NCs) and a Z-scheme covalent organic framework/silver sulfide (T-COF/Ag2S) composite. This Z-scheme T-COF/Ag2S composite accelerates electron transfer and produces an excellent initial photocurrent. When CRISPR/Cas13a precisely targets circRNA, it nonspecifically cleaves the triple-helix molecular structure to release DNA fragments (C'/C"). After the C'/C" opens the DNA hairpin probe (HP) modified on the electrode, hybridization chain reactions are performed to produce abundant AT-rich double-stranded DNA with the addition of H1 and H2 probes. Upon the incubation of Cu2+, Cu NCs are in situ formed via the A-Cu2+-T bonds and can effectively quench the photocurrent of the Z-scheme T-COF/Ag2S due to the energy transfer process. This developed PEC biosensor for the circRNA assay shows a low limit of detection of 0.5 fM, and the reusability of DNA-modified magnetic beads (MB-DNA) reduces the detection cost. Moreover, the PEC biosensor can accurately quantify the circRNA level and distinguish the circRNA expression in whole blood from healthy controls and lung cancer patients, offering strong potential in clinical diagnosis.

Direct Partial Transformation of 2D Antimony Oxybromide to Halide Perovskite Heterostructure for Efficient CO2 Photoreduction

The photocatalytic activity of lead-free perovskite heterostructures currently suffers from low efficiency due to the lack of active sites and the inadequate photogenerated carrier separation, the latter of which is hindered by slow charge transfer at the heterostructure interfaces. Herein, a facile strategy is reported for the construction of lead-free halide-perovskite-based heterostructure with swift interfacial charge transfer, achieved through direct partial conversion of 2D antimony oxybromide Sb4O5Br2 to generate Cs3Sb2Br9/Sb4O5Br2 heterostructure. Compared to the traditional electrostatic self-assembly method, this approach endows the Cs3Sb2Br9/Sb4O5Br2 heterostructure with a tightly interconnected interface through in situ partial conversion, significantly accelerating interfacial charge transfer and thereby enhancing the separation efficiency of photogenerated carriers. The cobalt-doped Cs3Sb2Br9/Sb4O5Br2 heterostructure demonstrates a record-high electron consumption rate of 840 µmol g-1 h-1 for photocatalytic CO2 reduction to CO coupled with H2O oxidation to O2, which is over 74- and 16-fold higher than that of individual Sb4O5Br2 and Cs3Sb2Br9, respectively. This work provides an effective strategy for promoting charge separation in photocatalysts to improve the performance of artificial photosynthesis.

Recent Advances in Metal Halide Perovskites for CO2 Photocatalytic Reduction: An Overview and Future Prospects

The photocatalytic reduction of CO2 into valuable chemicals and fuels has become a significant research focus in recent years due to its environmental sustainability and energy efficiency. Metal halide perovskites (MHPs), renowned for their remarkable optoelectronic properties and tunable structures, are regarded as promising photocatalysts. Yet, their practical uses are constrained by inherent instability, severe electron-hole recombination, and a scarcity of active sites, prompting substantial research efforts to optimize MHP-based photocatalysts. This review summarizes the latest advancements in MHP-based photocatalysis. First the fundamental principles of photocatalysis are outlined and the structural and optical characteristics of MHPs are evaluated. Then key strategies for enhancing MHP photocatalysts, including morphology and surface modification, encapsulation, metal cation doping, heterojunction engineering, and molecular immobilization are highlighted. Finally, considering recent research progress and the needs for industrial application, challenges and future prospects are explored. This review aims to support researchers in the development of more efficient and stable MHP-based photocatalysts.

Construction of a CoNiHHTP MOF/PHI Z-Scheme Heterojunction for ppb Level NO2 Photoelectric Sensing with 405 nm Irradiation at RT

Ultrasensitive photoelectric detection of nitrogen dioxide (NO2) with PHI under visible light irradiation at room temperature (RT) remains an ongoing challenge due to the low charge separation and scarce adsorption sites. In this work, a dimensionally matched ultrathin CoNiHHTP MOF/PHI Z-scheme heterojunction is successfully constructed by taking advantage of the π-π interactions existing between the CoNiHHTP MOF and PHI. The amount-optimized heterojunction possesses a record detection limit of 1 ppb (response = 15.6%) for NO2 under 405 nm irradiation at RT, with reduced responsive (3.6 min) and recovery (2.7 min) times, good selectivity and reversibility, and long-time stability (150 days) compared with PHI, even superior to others reported at RT. Based on the time-resolved photoluminescence spectra, in situ X-ray photoelectron spectra, and diffuse reflectance infrared Fourier transform spectroscopy results, the resulting sensing performance is attributed to the favorable Z-scheme charge transfer and separation. Moreover, the Ni nodes favorably present in adjacent metal sites between the lamellae contribute to charge transfer and redistribution, whereas Co nodes could act as selective centers for promoted adsorption of NO2. Interestingly, it is confirmed that the CoNiHHTP MOF/PHI heterojunction could effectively reduce the influence of O2 in the gas-sensitive reaction due to their unique bimetallic (Co and Ni) nodes, which is also favorable for the improved sensing performances for NO2. This work provides a feasible strategy to develop promising PHI-based optoelectronic gas sensors at RT.

Efficient Homojunction/Heterojunction Photocatalyst via Integrating CsPbBr3 Quantum Dot Homojunction with TiO2 for Degradation of Organic Dyes

A novel TiO2-CsPbBr3(Q) photocatalyst is proposed and rationally constructed, where CsPbBr3 perovskite quantum dots (QDs) of various sizes inside mesopore TiO2 (M-TiO2) are integrated. These perovskite QDs, generated in situ within M-TiO2, establish a type-II homojunction. Interestingly, a Z-scheme heterojunction is simultaneously formed at the interface between CsPbBr3 and TiO2. Due to the coexistence of the type-II homojunction and the Z-scheme heterojunction, photogenerated electrons are effectively transferred from TiO2 to CsPbBr3, thereby suppressing carrier recombination and thus enhancing the degradation of rhodamine B (RhB). Compared with pure CsPbBr3 and TiO2, TiO2-CsPbBr3(Q) shows significantly enhanced photocatalytic performance for RhB degradation. The degradation efficiency of RhB in the presence of the TiO2-CsPbBr3(Q) attains 97.7% in 5 min under light illumination, representing the highest efficiency observed among photocatalysts based on TiO2. This study will facilitate the development of superior semiconductor catalysts for photocatalytic applications.

All-inorganic lead halide perovskites for photocatalysis: a review

Nowadays, environmental pollution and the energy crisis are two significant concerns in the world, and photocatalysis is seen as a key solution to these issues. All-inorganic lead halide perovskites have been extensively utilized in photocatalysis and have become one of the most promising materials in recent years. The superior performance of all-inorganic lead halide perovskites distinguish them from other photocatalysts. Since pure lead halide perovskites typically have shortcomings, such as low stability, poor active sites, and ineffective carrier extraction, that restrict their use in photocatalytic reactions, it is crucial to enhance their photocatalytic activity and stability. Huge progress has been made to deal with these critical issues to enhance the effects of all-inorganic lead halide perovskites as efficient photocatalysts in a wide range of applications. In this manuscript, the synthesis methods of all-inorganic lead halide perovskites are discussed, and promising strategies are proposed for superior photocatalytic performance. Moreover, the research progress of photocatalysis applications are summarized; finally, the issues of all-inorganic lead halide perovskite photocatalytic materials at the current state and future research directions are also analyzed and discussed. We hope that this manuscript will provide novel insights to researchers to further promote the research on photocatalysis based on all-inorganic lead halide perovskites.