No abstract

Interstitial P doping is more effective in improving the photocatalytic activity compared with substitutional P doping.

No abstract

Fe 3+ -doped g-C 3 N 4 and Fe 2 O 3 /g-C 3 N 4 composite catalysts were prepared by a simple method using melamine and ferric nitrate as precursors. X-ray diffraction, UV-Vis spectroscopy, Fourier transform infrared spectra, scanning electron microscopy, photoluminescence, X-ray photoelectron spectroscopy and photocurrent measurements were used to characterize the prepared catalysts. The results indicated that Fe 3+ was inserted at an interstitial position of g-C 3 N 4 by coordinating to N atoms, which exist in a form completely different from those in the Fe 2 O 3 /g-C 3 N 4 composite. The different form of Fe species caused the difference in optical properties, energy band structure and electrons-holes separation rate.The activities of Fe 3+ -doped g-C 3 N 4 and Fe 2 O 3 /g-C 3 N 4 composite catalysts were tested by the photocatalytic degradation of Rhodamine B (RhB) under visible light. The rate constant of Fe 3+ -doped g-C 3 N 4 was 2.5 and 1.8 times higher than that of the g-C 3 N 4 and Fe 2 O 3 /g-C 3 N 4 composite. The possible mechanism is proposed.

No abstract

No abstract

Oxygen vacancies (OVs) can improve catalytic activities in oxygen evolution reaction (OER). Although considerable effort has been devoted to increasing the OVs concentration in electrocatalysts, limited OVs have been created by current techniques so far. Here, we, for the first time, engineered (i.e., created) abundant OVs into perovskites by element doping and plasma treatment. The results revealed that more OVs were manufactured by combination of Sr doping with Ar plasma treatment, leading to improved OER activity and high stability of LaCoO 3 perovskite. The La 1-x Sr x CoO 3-δ (x = 0.3) sample with Ar plasma treatment (denoted as Sr-0.3-p) showed high OER activity and stability due to the existence of rich OVs, which provided large amounts as well as high intrinsic activity of active sites in OER. The combination of two OV-creating techniques provides an efficient strategy to develop OV-rich catalysts for various applications.

Perovskites are known for their high yield photoluminescence and higher photovoltaic conversion efficiencies. To make them practically useful, the toxicity and stability issues need to be addressed. Herein, we report a less toxic and stable silver bismuth iodide quantum dot system, prepared by a modified ligand assisted reprecipitation (LARP) method. Three types of phase structures such as AgBiI 4 , Ag 2 BiI 5 , and AgBi 2 I 7 were obtained, and their structural and photophysical properties were investigated. By replacing lead (Pb), the toxicity would be reduced considerably and the optical properties persisted for more than six months at ambient conditions. The as-prepared silver bismuth iodide QDs were then used to construct photodetector devices, and the device performances were studied. The constructed photodetector devices have generated the photocurrent values of (AgBi 2 I 7 ∼ 0.12 and 0.32 mA), (Ag 2 BiI 5 ∼ 0.87 and 1.6 μA), and (AgBiI 4 ∼ 0.16 and 0.61 mA) at different biasing voltages of 0.1 and 0.2 V, respectively, under visible light irradiation. The AgBi 2 I 7 QD system generated higher photocurrent value and exhibited a better ON/OFF ratio of (I on /I off = 6.5 × 10 4 ). The silver bismuth iodide QDs based photodetectors are promising for ultraviolet photodetection.