Near-Infrared-Responsive Photocatalytic CO₂ Conversion via In Situ Generated Co₃O₄/Cu₂O

Abstract

Photocatalytic CO2 conversion to fuels is a promising strategy for achieving global carbon neutrality. However, infrared light, which accounts for ∼50% of the full sunlight spectrum, has not yet been effectively utilized via photocatalysis. Here, we present an approach to directly power photocatalytic CO2 reduction using near-infrared light. This near-infrared light-responsive process occurs on an in situ generated Co3O4/Cu2O photocatalyst with a nanobranch structure. Photoassisted Kelvin probe force microscopy and relative photocatalytic measurements demonstrate the increase of surface photovoltage after illumination by near-infrared light. We also find that Cu(I) on this in situ generated Co3O4/Cu2O could facilitate the formation of a *CHO intermediate, thus enabling a high-performance CH4 production with a yield of 6.5 μmol/h and a selectivity of 99%. Moreover, we perform a practically oriented direct solar-driven photocatalytic CO2 reduction under concentrated sunlight and achieve a fuel yield of 12.5 μmol/h.

Synthesis of Dual p–n Heterojunction of Ni/Mn-MOF-74/CdS@Co3O4 Photocatalyst as a Photoassisted Fenton-like Catalyst for Removal of Tetracycline Hydrochloride

“…The E fb of Co 3 O 4 was 2.06 V, which corresponded to a VB potential of 2.26 eV vs NHE and a CB potential of 0.22 eV vs NHE. false( α italichv false) 1 / n = A ( hv − E normalg ) E g = E VB − E CB Based on the above analysis, the energy band positions of n-type semiconductor Ni/Mn-MOF-74, n-type semiconductor CdS, and p-type semiconductor Co 3 O 4 before and after contact are shown in Figure g,h. The Fermi level of n-type semiconductor Ni/Mn-MOF-74 and CdS was closer to its CB, and the Fermi level of p-type semiconductor Co 3 O 4 was closer to VB. , When a p–n heterojunction was created, the p- and n-type semiconductors came into direct contact. This caused the band structure of the semiconductor to bend, resulting in the alignment of the Fermi levels of the p-type and n-type semiconductors.…”

“…In order to differentiate between direct photooxidation with holes and indirect photooxidation with • O 2 – and OH • radicals, a series of experiments were conducted. These experiments involved the use of p-benzoquinone (PBQ) to quench • O 2 – radicals, citric acid (CA) to quench holes, and tert -butyl alcohol (TBA) to quench OH • radicals. , As depicted in Figure d, the addition of a quencher for • O 2 – radicals ( p -benzoquinone) led to a noticeable change in the degradation rate of TC. This indicated that the photoinduced electrons remained in the CB of Ni/Mn-MOF-74 and did not transfer to the CB of CdS.…”

“…2)Based on the above analysis, the energy band positions of n-type semiconductor Ni/Mn-MOF-74, n-type semiconductor CdS, and p-type semiconductor Co 3 O 4 before and after contact are shown in Figure4g,h. The Fermi level of n-type semiconductor Ni/Mn-MOF-74 and CdS was closer to its CB, and the Fermi level of p-type semiconductor Co 3 O 4 was closer to VB 36,37. When a p−n heterojunction was created, the p-and n-type semiconductors came into direct contact.…”

Photothermal Effect- and Interfacial Chemical Bond-Modulated NiOx/Ta3N5 Heterojunction for Efficient CO2 Photoreduction

“…An efficient photothermal catalytic CO 2 reduction system should possess key features such as wide-spectrum absorption, effective photo-to-heat conversion, strong light-induced charge separation, multiple catalytic active sites, and a low energy barrier for CO 2 activation and conversion. Coupling a photothermal component with a photochemical active unit to construct heterojunctions holds great promise for maximizing photothermal CO 2 reduction activity. , This approach integrates the driving forces of both photocatalytic and thermal active components for breaking the CO bond in CO 2 . Additionally, it promotes charge carrier separation via a built-in heterojunction and affords multiple catalytic active sites accompanied by synergetic charge redistribution.…”

“…Coupling a photothermal component with a photochemical active unit to construct heterojunctions holds great promise for maximizing photothermal CO 2 reduction activity. 20,21 This approach integrates the driving forces of both photocatalytic and thermal active components for breaking the C�O bond in CO 2 . Additionally, it promotes charge carrier separation via a built-in heterojunction and affords multiple catalytic active sites accompanied by synergetic charge redistribution.…”