Carbon quantum dots as a visible light sensitizer to significantly increase the solar water splitting performance of bismuth vanadate photoanodes

Abstract

Our photoanode has achieved a record high photocurrent density and applied bias photon-to-current efficiency for BiVO4-based photoanodes.

CQD-Based Composites as Visible-Light Active Photocatalysts for Purification of Water

“…Carbon quantum dot appears to be such a material. It is easy to produce, cheap, nontoxic, green, stable, and abundant [1,58,59]. Additionally, it displays strong blue photoluminescence and good optical absorption in the UV and near-visible region [60].…”

“…Secondly, the CQDs with upconversion PL properties can convert longer wavelength light to the short wavelength light, which in turn can excite a wide bandgap photocatalyst (ZnO) to form e Recently, several reports have been published that show CQDs to dramatically extend the optical absorption range of wide and narrow bandgap photocatalysts to the entire visiblelight range and beyond [18-21, 58, 60, 62, 68-71]. For example, in a recent publication, Ye et al [58] reported using CQDs to extend the light absorption range of BiVO 4 to the entire visible range. The resulting CQD/BiVO 4 composite photocatalyst achieved an absolute photocurrent density J abs of 9:2mAcm À2 as shown in Figure 6(a).…”

“…A photosensitizer is excited by low-energy photons to generate electrons that are subsequently injected into the conduction band of the wide bandgap photocatalyst. The common photosensitizers are usually characterized as expensive [53][54][55], toxic [56], unstable [57], and polluting [58]. These drawbacks limit the practical and large-scale application of conventional photosensitizers.…”

A novel CoOOH/(Ti, C)-Fe2O3 nanorod photoanode for photoelectrochemical water splitting

“…Applied bias photo-to-current efficiency (ABPE) can be expressed as [12]: ABPE=[J PEC ×(1.23−V app )]/P light , where J PEC is the photocurrent density of samples, V app is the applied external potential vs. RHE and P light is the power density of the illumination (100 mW cm −2 ).…”

“…The photoelectrodes are the key factors to the efficiency of PEC water splitting like the leaves of photosynthesis in the nature [4]. Many efforts have been devoted to exploring highly active photoanode materials such as TiO 2 [6,7], ZnO [8,9], Nb 2 O 5 [10], BiVO 4 [11,12] and WO 3 [13][14][15].…”