The objective of photocatalytic CO2 reduction (PCR) is to achieve high selectivity for a single energy‐bearing product with high efficiency and stability. The bulk configuration usually determines charge carrier kinetics, whereas surface atomic arrangement defines the PCR thermodynamic pathway. Concurrent engineering of bulk and surface structures is therefore crucial for achieving the goal of PCR. Herein, an ultrastable and highly selective PCR using homogeneously doped BiOCl nanosheets synthesized via an inventive molten strategy is presented. With B2O3 as both the molten salt and doping precursor, this new doping approach ensures boron (B) doping from the surface into the bulk with dual functionalities. Bulk B doping mitigates strong excitonic effects confined in 2D BiOCl by significantly reducing exciton binding energies, whereas surface‐doped B atoms reconstruct the BiOCl surface by extracting lattice hydroxyl groups, resulting in intimate B‐oxygen vacancy (B‐OV) associates. These exclusive B‐OV associates enable spontaneous CO2 activation, suppress competitive hydrogen evolution and promote the proton‐coupled electron transfer step by stabilizing *COOH for selective CO generation. As a result, the homogeneous B‐doped BiOCl nanosheets exhibit 98% selectivity for CO2‐to‐CO reduction under visible light, with an impressive rate of 83.64 µmol g−1 h−1 and ultrastability for long‐term testing of 120 h.

The photocatalytic O 2 activation for pollutant removal highly depends on the controlled generation of desired reactive oxygen species (ROS). Herein, we demonstrate that the robust excitonic effect of BiOBr nanosheets, which is prototypical for singlet oxygen ( 1 O 2 ) production to partially oxidize NO into a more toxic intermediate NO 2 , can be weakened by surface boronizing via inducing a staggered band alignment from the surface to the bulk and simultaneously generating more surface oxygen vacancy (V O ). The staggered band alignment destabilizes excitons and facilitates their dissociation into charge carriers, while surface V O traps electrons and efficiently activates O 2 into a superoxide radical ( • O 2 − ) via a one-electron-transfer pathway. Different from 1 O 2 , • O 2 − enables the complete oxidation of NO into nitrate with high selectivity that is more desirable for safe indoor NO remediation under visible light irradiation. This study provides a facile excitonic effect manipulating method for layered two-dimensional photocatalysts and sheds light on the importance of managing ROS production for efficient pollutant removal.

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Background Protein tyrosine kinase 7 (PTK 7) is a membrane receptor, which can be found in various kinds of cancers. In view of this, detection of PTK 7 in the peripheral circulation would be an effective way for the early diagnosis of cancer. Results In this work, a multi-carbon dots and aptamer-based signal amplification ratiometric fluorescence probe was developed. The fluorescence of the aptamer-modified y-CDs and b-CDs were respectively chosen as the detection signal and interior label. The fluorescence of y-CDs was quenched by Fe3O4 and cDNA (complement to aptamer) compound without PTK 7, but recovered by the addition of PTK 7. Then, the free aptamer was cut by DNase I, which amplified the detection signal. The ratiometric fluorescence sensor for PTK 7 was established with the LOD of 0.016 ng mL−1. Conclusions Summary, a multi-carbon dots and aptamer-based signal amplification ratiometric fluorescence probe was developed for the detection of protein tyrosine kinase 7. The developed probe was applied to PTK 7 detection in MCF-7 cells and human serum with satisfying results, thus indicating that this probe has huge potential in clinical practice.