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The production of hydrogen fuel by solar-driven photocatalytic water splitting is an attractive solution to overcome the environmental and energy problems with traditional fossil fuels. The strategies to improve the capacity of photocatalytic hydrogen production include enhancing the light absorption of materials and using co-catalysts to reduce the efficiency of electron–hole recombination. Here, we report a Schottky heterojunction photocatalyst composed of subphthalocyanine (SubPc) and Ti3C2Tx MXene, which can effectively separate photogenerated charges. The outstanding ability of SubPc to absorb visible light and the ability of Ti3C2Tx MXene to capture photogenerated electrons were applied to improve the photocatalytic hydrogen-production performance of the SubPc/Ti3C2Tx composite. Two types of SubPcs (SubPc-Cl and SubPc-OPh) were hybridized with Ti3C2Tx MXene nanosheets. The hydrogen evolution of SubPc/Ti3C2Tx with different mass ratios was experimentally investigated, and it was found that the optimized SubPc-Cl/Ti3C2Tx exhibited the best H2-production rate of 105 μmol g−1 h−1. Our findings provide a new design approach and promising strategy to develop low-cost photocatalysts for future solar-driven sustainable energy-conversion systems. [ABSTRACT FROM AUTHOR]

Interface engineering to enhance carrier extraction and transfer capability, as well as controlling the morphology and defects of perovskite films, remains an imperative challenge in perovskite photovoltaics. Herein, we introduce an innovative method utilizing an oxidized derivative of Nb2CTx MXene to regulate the interface between the electron transport layer (ETL) and perovskite. The oxidation of Nb2CTx results in the formation of a hybrid structure comprising Nb2CTx and Nb2O5. This oxidized derivative (namely O–Nb2C) provides better energy level alignment and facilitated carrier extraction, leading to optimized charge transfer and reduced electron–hole recombination. Moreover, O–Nb2C conducts more surface functional groups associated with the enhancement of surface free energy. This enhancement is presumed to promote the homogeneous nucleation of the perovskite precursor, resulting in improved crystallization of perovskite films with less trap density. Consequently, the perovskite solar cell (PSC) with the O–Nb2C regulation delivers a boost in power conversion efficiency (PCE) to 23.20%, surpassing the baseline PCE of 20.51% based on SnO2, and demonstrates a minimal PCE decay of less than 15% after 1500 hours of storage. This work presents a robust method of interfacial engineering utilizing MXene derivatives for high-performance PSCs, thereby further expanding the applications of MXenes in photovoltaic devices. [ABSTRACT FROM AUTHOR]

The idea of exploiting the inexhaustible solar energy-driven photocatalytic hydrogen evolution reaction (HER) to generate hydrogen energy, a sustainable clean energy source, to solve problems such as fossil fuel-induced greenhouse gas emissions is believed to be a feasible strategy. However, photocatalytic HER is inefficient due to insufficient light trapping capability and low charge separation efficiency of the single semiconductor material employed. Therefore, it remains a great challenge to achieve fast and efficient photocatalytic HER. In this work, a novel ternary Chl@Cu2O/Ti3C2Tx photocatalyst with an organic–inorganic heterojunction structure has been designed by employing a stepwise deposition process for efficient solar energy conversion to hydrogen. The results showed that the photocatalytic activity of Chl@Cu2O/Ti3C2Tx organic–inorganic heterojunction photocatalysts for HER was significantly improved compared with that of single Chl@Ti3C2Tx and Cu2O/Ti3C2Tx. The improvement of the photocatalytic performance of Chl@Cu2O/Ti3C2Tx compared to Chl@Ti3C2Tx and Cu2O/Ti3C2Tx is attributed to the construction of the Chl–Cu2O organic–inorganic heterojunction structure in Chl@Cu2O/Ti3C2Tx, which extends the absorption range of the spectra and dramatically enhances the separation efficiency of the photogenerated carriers in Chl@Cu2O/Ti3C2Tx composites. [ABSTRACT FROM AUTHOR]

The idea of exploiting the inexhaustible solar energy-driven photocatalytic hydrogen evolution reaction (HER) to generate hydrogen energy, a sustainable clean energy source, to solve problems such as fossil fuel-induced greenhouse gas emissions is believed to be a feasible strategy. However, photocatalytic HER is inefficient due to insufficient light trapping capability and low charge separation efficiency of the single semiconductor material employed. Therefore, it remains a great challenge to achieve fast and efficient photocatalytic HER. In this work, a novel ternary Chl@Cu2O/Ti3C2Tx photocatalyst with an organic–inorganic heterojunction structure has been designed by employing a stepwise deposition process for efficient solar energy conversion to hydrogen. The results showed that the photocatalytic activity of Chl@Cu2O/Ti3C2Tx organic–inorganic heterojunction photocatalysts for HER was significantly improved compared with that of single Chl@Ti3C2Tx and Cu2O/Ti3C2Tx. The improvement of the photocatalytic performance of Chl@Cu2O/Ti3C2Tx compared to Chl@Ti3C2Tx and Cu2O/Ti3C2Tx is attributed to the construction of the Chl–Cu2O organic–inorganic heterojunction structure in Chl@Cu2O/Ti3C2Tx, which extends the absorption range of the spectra and dramatically enhances the separation efficiency of the photogenerated carriers in Chl@Cu2O/Ti3C2Tx composites. [ABSTRACT FROM AUTHOR]

Exosomes are nanovesicles secreted by cells, which play a crucial role in various pathological processes. Exosomes have shown great promise as tumor biomarkers because of the abundant secretion during tumor formation. The development of a convenient, efficient, and cost-effective method for simultaneously enriching and detecting exosomes is of utmost importance for both basic research and clinical applications. In this study, an aptamer-functionalized magnetic Ti 3 C 2 composite material (Fe 3 O 4 @Ti 3 C 2 @PEI@DSP@aptamer@FAM-ssDNA) is prepared for the simultaneous enrichment and detection of exosomes. CD63 aptamers are utilized to recognize and capture the exosomes, followed by magnetic separation. The exosomes are then released by cleaving the disulfide bonds of DSP. Compared to traditional methods, Fe 3 O 4 @Ti 3 C 2 @PEI@DSP@aptamer@FAM-ssDNA exhibited superior efficiency in enriching exosomes while preserving their structural and functional integrity. Detection of exosome concentration is achieved through the fluorescence quenching of Ti 3 C 2 and the competitive binding between the exosomes and a fluorescently labeled probe. This method exhibited a low detection limit of 4.21 × 10 4 particles mL -1 , a number that is comparable to the state-of-the-art method in the detection of exosomes. The present study demonstrates a method of simultaneous enrichment and detection of exosomes with a high sensitivity, accuracy, specificity, and cost-effectiveness providing significant potential for clinical research and diagnosis., (© 2024 Wiley‐VCH GmbH.)

Aqueous manganese ion batteries hold potential for stationary storage applications owing to their merits in cost, energy density, and environmental sustainability. However, the formidable challenge is the instability of metallic manganese (Mn) anodes in aqueous electrolytes due to severe hydrogen evolution reaction (HER), which is more serious than the commonly studied Zn metal anodes. Moreover, the mechanism of HER side reactions has remained unclear. Herein, we design a series of Mn-P alloying anodes by precisely regulating their energy band structures to mitigate the HER issue. It is found that the serious HER primarily originates from the spontaneous Mn-H2O reaction driven by the excessively high HOMO energy level of Mn, rather than electrocatalytic water splitting. Owing to a reduced HOMO energy level and enhanced electron escape work function, the MnP anode achieves an evidently enhanced cycle durability (over 1000 hours at a high current density of 5 mA cm-2). The MnP||AgVO full cell with an N/P ratio of 4 exhibits better rate capability and extended cycle life (7000 cycles) with minimal capacity degradation than the cell using metallic Mn anode (less than 100 cycles). This study provides a practical approach for developing highly durable aqueous Mn ion batteries., (© 2024 Wiley‐VCH GmbH.)

In the realm of photovoltaic research, 2D transition metal carbides (MXenes) have gained significant interest due to their exceptional photoelectric capabilities. However, the instability of MXenes due to oxidation has a direct impact on their practical applications. In this work, the oxidation process of Nb 2 CT x MXene in aqueous systems is methodically simulated at the atomic level and nanosecond timescales, which elucidates the structural variations influenced by the synergistic effects of water and dissolved oxygen, predicting a transition from metal to semiconductor with 44% C atoms replaced by O atoms in Nb 2 CT x . Moreover, Nb 2 CT x with varying oxidation degrees is utilized as electron transport layers (ETLs) in perovskite solar cells (PSCs). Favorable energy level alignments with superior electron transfer capability are achieved by controlled oxidation. By further exploring the composites of Nb 2 CT x to its derivatives, the strong interaction of the nano-composites is demonstrated to be more effective for electron transport, thus the corresponding PSC achieves a better performance with long-term stability compared with the widely used ETLs like SnO 2 . This work unravels the oxidation dynamics of Nb 2 CT x and provides a promising approach to designing ETL by exploiting MXenes to their derivatives for photovoltaic technologies., (© 2024 Wiley‐VCH GmbH.)