Search

The pursuit of developing highly potent and environmentally friendly photocatalysts for water dissociation is crucial for the advancement and storage of unlimited solar energy, although it remains a massive challenge. Herein, we conducted a screening process for the photocatalytic water splitting capabilities of a multitude of members from the extensive MA2N4 family. Using first-principles calculations, we found MoSi2N4, WSi2N4 and WGe2N4 structures with excellent potential for photocatalytic applications. To be specific, these members possess semiconductor characteristics, featuring suitable band gap structures and pronounced optical absorption capabilities in the UV-visible light spectrum. Our findings suggest that with nitrogen vacancies present on the surface, MoSi2N4, WSi2N4, and WGe2N4 all demonstrate near-zero Gibbs free energy in driving the hydrogen evolution reaction. Simultaneously, MoSi2N4, WSi2N4, and WGe2N4 can spontaneously catalyze the overall water splitting reaction under light illumination at pH values of 4, 12, and 8, respectively. This investigation provides fresh perspectives in terms of designing highly efficient photocatalysts. [ABSTRACT FROM AUTHOR]

Ambiguous sentences as a difficult point in the teaching of Chinese as a foreign language have always affected the two-language acquisition of two-language learners, this paper analyzes based on the bias in the process of two-language acquisition, uses observation method and causal analysis method to analyze the causes of ambiguous sentences as research points, and finds that the classification of traditional ambiguous sentences is mostly carried out at three levels, but the ambiguity of two-language learners in addition to three planes also includes the difference between pronunciation and vocabulary and puts forward the following suggestions from the perspective of Chinese international education: pay attention to the choice of words 3. Pay attention to word order teaching, appropriate use of punctuation, appropriate change of sentence pattern. I hope to contribute to the development of ambiguous sentence teaching in Chinese international education.

The detection of hazardous CO gas is an important research content in the domain of the Internet of Things (IoT). Herein, we introduced a facile metal-organic frameworks (MOFs)-templated strategy to synthesize Cd-doped Co3O4 nanosheets (Cd-Co3O4 NSs) aimed at boosting the CO-sensing performance. The synthesized Cd-Co3O4 NSs feature a multihole nanomeshes structure and a large specific surface area (106.579 m2·g-1), which endows the sensing materials with favorable gas diffusion and interaction ability. Furthermore, compared with unadulterated Co3O4, the 2 mol % Cd-doped Co3O4 (2% Cd-Co3O4) sensor exhibits enhanced sensitivity (244%) to 100 ppm CO at 200 °C and a comparatively low experimental limit of detection (0.5 ppm/experimental value). The 2% Cd-Co3O4 NSs show good selectivity, reproducibility, and long-term stability. The improved CO sensitivity signal is probably owing to the stable nanomeshes construction, high surface area, and rich oxygen vacancies caused by cadmium doping. This study presents a facile avenue to promote the sensing performance of p-type metal oxide semiconductors by enhancing the surface activity of Co3O4 combined with morphology control and component regulation. [ABSTRACT FROM AUTHOR]

Black phosphorene (BP) is a metal-free two-dimensional photocatalyst with potential for visible-light-driven photocatalytic H2 evolution. However, its inert basal plane toward the HER hinders its practical application. To overcome this problem, we design a novel nonprecious metal–nonmetal co-doping method of BP to activate its inert basal plane and improve photocatalytic HER performance. Through density functional theory (DFT) calculations, we systematically investigate the photocatalytic performance of nonprecious metal and nonmetal co-doped BPs. Our results show that V–N co-doped BP exhibits excellent thermodynamic stability, suitable band structure, improved carrier separation, superior adsorption and dissociation energies and enhanced visible-light absorption coefficient. Importantly, V–N co-doping successfully activates the inert basal plane of BP, allowing it to drive the HER under illumination (ΔGH = −0.12 eV). This study highlights the potential of nonprecious metal–nonmetal co-doping to enhance the photocatalytic activity of BP, providing invaluable insights for advancing the field of co-doped BP in photocatalysis. [ABSTRACT FROM AUTHOR]