Interface modulation of BiVO4 based photoanode with Bi(III)Bi(V)O4 for enhanced solar water splitting

Bridging between NiAl-LDH and g-C3N4 by using carbon quantum dots for highly enhanced photoreduction of CO2 into CO

A series of treble NiAl-LDH/g-C₃N₄/carbon quantum dots (LDH/CN/CQDs) photocatalysts is successfully prepared for the photoreduction of CO₂ to CO via a facile hydrothermal pathway. In the 3D flower-like LDH/CN/CQDs, CQDs not only achieve the efficient inhibition of charge recombination but also act as the unhindered "electronic bridges" to synergistically construct a classical type-Ⅱ charge transfer configuration, which synchronously permits the effluence of photogenerated electrons from CN to LDH and holes from LDH to CN, and promotes ultraviolet-visible irradiation respondence. The sample of LDH/CN/CQDs-6 is the optimal one amongst the LDH/CN/CQDs with a larger special surface area (98.43 m²g^-1) and an appropriate content of CQDs (66.9 wt%), exhibiting the highest CO evolution rate (5.2 μmol·g^-1·h^-1) under visible light irradiation without any sacrificial agent or photosensitizer in water. This is 26.8- and 20.9-fold higher than those of the pristine LDH, pure CN, and their binary counterparts, respectively, and also outperforms most reported LDH-based photocatalysts. As unhindered electron conduction bridges, the highly dispersed CQDs in the LDH/CN heterojunction significantly increase utilization efficiency of light energy and separation efficiency of photogenerated electron-hole pairs. This work provides a beneficial attempt to integrate CQDs with LDH/CN for the positive synergetic effect on both photoelectric properties and electron transfer to obtain highly enhanced photocatalytic activity of CO₂ into CO, and expected to be extended towards broader photocatalytic applications.

Enhanced surface kinetics and charge transfer of BiVO4 photoanode by Rh2O3 cocatalyst loading for boosted solar water oxidation

The Rh 2 O 3 /BiVO 4 composite photoanode exhibits enhanced surface reaction kinetics and charge transfer efficiency, enabling a photocurrent density of ca. 3.5 mA/cm 2 at 1.23 V (vs. RHE), which is about 3.89 times higher than that of the pristine BiVO 4 , with a lower onset potential of 0.29 V (vs. RHE).