How does cell volume influence the total light absorption efficiency of a mixed population of dinoflagellates with similar cell shapes and pigment compositions?

Visible-light-driven hydrogen production through photocatalysis has attracted enormous interest owing to its great potential to address energy and environmental issues. However, photocatalysis possesses several limitations to overcome for practical applications, such as low light absorption efficiency, rapid charge recombination, and poor stability of photocatalysts. Here, the preparation of efficient noble metal–semiconductor hybrid photocatalysts for photocatalytic hydrogen production is presented. The prepared ternary Rh–TiO2–CeO2 hybrid photocatalysts exhibited excellent photocatalytic performance toward the hydrogen production reaction compared with their counterparts, ascribed to the synergistic combination of Rh, TiO2, and CeO2.

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Development of an improved two-sphere integration technique for quantifying black carbon concentrations in the atmosphere and seasonal snow

Atmospheric Measurement Techniques ◽

10.5194/amt-13-39-2020 ◽

2020 ◽

Vol 13 (1) ◽

pp. 39-52 ◽

Cited By ~ 1

Author(s):

Xin Wang ◽

Xueying Zhang ◽

Wenjing Di

Keyword(s):

Black Carbon ◽

Light Absorption ◽

Optical Method ◽

Theoretical Calculations ◽

Dominant Role ◽

Northern China ◽

Least Squares Regression ◽

Seasonal Snow ◽

Empirical Procedure ◽

Total Light

Abstract. An improved two-sphere integration (TSI) technique has been developed to quantify black carbon (BC) concentrations in the atmosphere and seasonal snow. The major advantage of this system is that it combines two distinct integrated spheres to reduce the scattering effect due to light-absorbing particles and thus provides accurate determinations of total light absorption from BC collected on Nuclepore filters. The TSI technique can be calibrated using a series of 15 filter samples of standard fullerene soot. This technique quantifies the mass of BC by separating the spectrally resolved total light absorption into BC and non-BC fractions. To assess the accuracy of the improved system, an empirical procedure for measuring BC concentrations with a two-step thermal–optical method is also applied. Laboratory results indicate that the BC concentrations determined using the TSI technique and theoretical calculations are well correlated (R2=0.99), whereas the thermal–optical method underestimates BC concentrations by 35 %–45 % compared to that measured by the TSI technique. Assessments of the two methods for atmospheric and snow samples revealed excellent agreement, with least-squares regression lines with slopes of 1.72 (r2=0.67) and 0.84 (r2=0.93), respectively. However, the TSI technique is more accurate in quantifications of BC concentrations in both the atmosphere and seasonal snow, with an overall lower uncertainty. Using the improved TSI technique, we find that light absorption at a wavelength of 550 nm due to BC plays a dominant role relative to non-BC light absorption in both the atmosphere (62.76 %–91.84 % of total light absorption) and seasonal snow (43.11 %–88.56 %) over northern China.

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