NaBH4-Reduction Induced Evolution of Bi Nanoparticles from BiOCl Nanoplates and Construction of Promising Bi@BiOCl Hybrid Photocatalysts

Abstract

In this work, we have synthesized BiOCl nanoplates (diameter 140–220 nm, thickness 60–70 nm) via a co-precipitation method, and then created Bi nanoparticles (diameter 35–50 nm) on the surface of BiOCl nanoplates via a NaBH4 reduction method. By varying the NaBH4 concentration and reaction time, the evolution of Bi nanoparticles was systematically investigated. It is demonstrated that with increasing the NaBH4 concentration (at a fixing reaction time of 30 min), BiOCl crystals are gradually reduced into Bi nanoparticles, and pure Bi nanoparticles are formed at 120 mM NaBH4 solution treatment. At low-concentration NaBH4 solutions (e.g., 10 and 30 mM), with increasing the reaction time, BiOCl crystals are partially reduced into Bi nanoparticles, and then the Bi nanoparticles return to form BiOCl crystals. At high-concentration NaBH4 solutions (e.g., 120 mM), BiOCl crystals are reduced to Bi nanoparticles completely with a short reaction time, and further prolong the treatment time leads to the transformation of the Bi nanoparticles into a two-phase mixture of BiOCl and Bi2O3 nanowires. The photodegradation performances of the samples were investigated by choosing rhodamine B (RhB) as the model pollutant and using simulated sunlight as the light source. It is demonstrated that an enhanced photodegradation performance can be achieved for the created Bi@BiOCl hybrid composites with appropriate NaBH4 treatment. The underlying photocatalytic mechanism was systematically investigated and discussed.

Effect of Ni doping on the structural, optical and photocatalytic activity of MoS2, prepared by Hydrothermal method

“…Such phenomena are leading the excited electrons to move from valance to conduction band in limited period of time. Hence with the increment of Ni contents the photodegradation for both MB and RhB dyes are enriching [36,37]. Figure 7 shows plot of C/C o versus irradiation time (C and C o are the residual and initial concentration dyes) for MB and RhB dyes.…”

A Perfect Absorber Based on Similar Fabry-Perot Four-Band in the Visible Range

“…Therefore, as the thickness of the dielectric layer increases, the center frequency will shift to the lower frequency. We can also find that the four absorption peaks, on the whole, show a trend of first increasing and then decreasing [50][51][52]. At the dielectric layer thickness of 100 nm, high peak values can be guaranteed at the four resonance positions.…”

High Quality Factor, High Sensitivity Metamaterial Graphene—Perfect Absorber Based on Critical Coupling Theory and Impedance Matching

“…Meanwhile, the ability of metamaterial absorbers to enhance absorption in the microwave, infrared, visible, and solar systems has also been demonstrated. Metamaterials have great potential in the control of light polarization, phase, and amplitude, which can be applied in optoelectronics, photonics, and photocatalysis [8][9][10][11][12][13][14][15][16][17][18][19]. Due to its super control of light, some new components can be developed, such as broadband circular polarizer, new perfect absorber and so on.…”