Enhanced Visible-Light-Driven H2 Production via UiO-66 Nanospheres Attached to Flower-Shaped ZnIn2S4 Microspheres

Abstract

Photocatalytic hydrogen production is an effective strategy for meeting energy challenges. Here, a composite for photocatalytic hydrogen production via introduction of UiO-66 nanospheres into flower-shaped ZnIn2S4 microspheres (ZIS/U6) is described. The optimum composite with 20 mg UiO-66 loading displayed the high photocatalytic rate of 1860.9 µmol g−1 h−1 with an apparent quantum efficiency of 1.4% at 420 nm under visible-light irradiation, which is nearly 3 times higher than that of ZnIn2S4. The improved photocatalytic H2 rate mainly benefited from effective electron transfer between ZnIn2S4 and UiO-66. Additionally, we tried to introduce UiO-66-NH2 and UiO-66-(SH)2 with excellent visible light absorption into ZnIn2S4 to obtain composites. Surprisingly, they did not exhibit better photocatalytic hydrogen production rates. Combined with the electrochemical test results, it was found that they had completely different electron transfer paths from ZIS/U6. Therefore, a different photocatalytic mechanism was proposed and further verified by transient photocurrent.

Multi-stepwise electron transfer via MOF-based nanocomposites for photocatalytic ammonia synthesis

“…Firstly, when the UPC photocatalyst is excited by absorbing photons from the irradiation, the photo-generated electrons and holes are generated in CNNS and organic ligands of UiO-66, as reported in previous studies. 7,34,35 On the one hand, the photo-generated electrons migrate from VB ( E vb = 1.99 V) to CB ( E cb = −0.92 V) of CNNS, and then transfer to the CB (−0.55 V) of UiO-66 through the conductive PDA layer. This can be further confirmed by the electron lifetime of UPC (8.1 ns) being superior among those of UC (7.4 ns), UiO-66 (6.9 ns) and CNNS (3.3 ns); on the other hand, the electrons can also transfer from VB ( E vb = 3.46 V) to CB ( E cb = −0.55 V) of UiO-66.…”

Uniform-embeddable-distributed Ni3S2 cocatalyst inside and outside a sheet-like ZnIn2S4 photocatalyst for boosting photocatalytic hydrogen evolution

“…4c), suggesting the excellent photocatalytic hydrogen-evol- ution performance of UEDNiS/ZIS. 10,[28][29][30][31][32][33][34] The cyclic stability of the catalyst in photocatalytic hydrogen-production tests over UEDNiS/ZIS was investigated. As displayed in Fig.…”

A Review and Recent Developments in Full‐Spectrum Photocatalysis using ZnIn2S4‐Based Photocatalysts

“…[26] Different polymorphs of ZIS have different applications. Many studies have revealed that the hexagonal ZIS and the cubic-phase ZIS have excellent photocatalytic activity under visible [27][28][29] and NIR light [30,31] irradiation and exhibit considerable chemical stability. For example, the hexagonal ZIS flower-like microspheres doped with black phosphorus quantum dots (QDs) prepared by Pan et al have excellent photocatalytic hydrogen evolution activity.…”

“…The synthesis of MOF-derived materials requires an organic solvent environment. This excellent composite material composed of ZIS and MOFs, such as UiO-66, [28,94,95] UiO-66-(COOH) 2 , [96] NH 2 -UiO-66, [97] MIL-125(Ti), [98] and NH 2 -MIL-125(Ti), [99,100] has been prepared through the solvothermal method. For example, Peng et al prepared the novel nanostructured UiO-66@ZIS photocatalysts by coating ZIS nanosheets on UiO-66 nanospheres by a simple solvothermal method, and the samples synthesized by this method had uniform structures and improved photocatalytic activity for hydrogen production under visible light illumination, as shown in Figure 9.…”