Metal–Organic Framework-Derived Tubular In₂O₃–C/CdIn₂S₄ Heterojunction for Efficient Solar-Driven CO₂ Conversion

Abstract

Realizing high-efficiency solar-driven CO2 reduction to chemicals and fuels requires high-performance photocatalysts with high utilization efficiency of solar light, efficient charge separation and transfer, and robust adsorption capacity for CO2. In this work, a tubular In2O3–C/CdIn2S4 (IOC/CIS) ternary heterojunction with an intimate interfacial contact was fabricated by pyrolysis of In-MIL-68 and subsequent solvothermal synthesis of CdIn2S4. The construction of a heterojunction promotes the separation and transfer efficiency of photogenerated carriers. The introduction of carbon not only accelerates the interfacial charge migration but also enhances light absorption and CO2 adsorption. The resulting 5IOC/CIS sample presents a remarkably improved photocatalytic CO2 reduction activity with a CO generation rate of 2432 μmol g–1 h–1, much higher than that of the In2O3/CdIn2S4 (IO/CIS) heterojunction (1906 μmol g–1 h–1). Furthermore, the type II charge transfer mechanism of the heterojunction was confirmed by the electron paramagnetic resonance characterization. This work provides new insight into the design and preparation of a highly efficient hollow heterojunction for photocatalytic applications.

Porous In2O3 Hollow Tube Infused with g-C3N4 for CO2 Photocatalytic Reduction

“…The flat band potentials of g-C 3 N 4 and IT obtained from the intercepts on the x axis are −1.02 and −0.86 V (vs NHE, pH = 7) (Figure a,b), respectively. From the literature, the flat band potential is about 0.1 V positive than the conduction band (CB) potential, so the CB values of g-C 3 N 4 and IT are −1.12 and −0.96 V (vs NHE, pH = 7), respectively. These CB values are higher than the reduction potential (−0.53 V) of CO 2 to CO, fulfilling the thermodynamic requirement of such a reaction .…”

“…41 For example, Wang et al synthesized a sandwich-like In 2 O 3 −ZnIn 2 S 4 tubular heterojunction from MIL-68-(In) with excellent performance on CO 2 photocatalytic reduction, 42 and Zhao et al reported on utilizing MOFs for the construction of carbon-coated ITs with CdIn 2 S 4 . 43 Nevertheless, it is still challenging to incorporate metal-free polymer semiconductors into MOF derivatives with compact and intimate particle arrangements. In our work, the MOF enabled the formation of a compact and staggered arrangement between g-C 3 N 4 and In 2 O 3 , maximizing direct contact between the phases for improved charge separation across the interface.…”

Photocatalytic conversion of 5-hydroxymethylfurfural to 2,5-diformylfuran by S-scheme black phosphorus/CdIn2S4 heterojunction

“…20,21 CdIn 2 S 4 , as an example of a chalcogenide semiconductor with a narrow band gap, has been widely researched because of its applications in various fields. 22,23 However, CdIn 2 S 4 has some limitations in practical applications, such as the high recombination efficiency of photogenerated electron–hole (e − –h + ) pairs, a narrow visible-light response range, and a limited number of active sites. These drawbacks limit its application in the photocatalytic selective oxidation of biomass platform molecules.…”

MOF-Derived Hollow Tubular In2O3/MIIIn2S4 (MII: Ca, Mn, and Zn) Heterostructures: Synergetic Charge-Transfer Mechanism and Excellent Photocatalytic Performance to Boost Activation of Small Atmospheric Molecules

“…The In 2 O 3 −C/CdIn 2 S 4 heterojunction performed outstanding photocatalytic activity toward CO 2 reduction. 32 Han et al fabricated a N-doped C-encapsulated In 2 O 3 −In 2 S 3 hollow dodecahedral heterostructure by sulfurization followed by carbonization of In-MOF and investigated their photocatalytic activity toward production of value-added chemicals. 33 Dai et al prepared a carbon-coated In 2 O 3 / ZnIn 2 S 4 hollow tubular heterostructure by calcination of MIL-68 (−NH 2 ) under N 2 atmosphere followed by a hydrothermal synthesis of ZnIn 2 S 4 .…”

“…have synthesized In 2 O 3 –C/CdIn 2 S 4 heterojunction photocatalytic materials by pyrolysis of MIL-68 under inert atmosphere followed by solvothermal synthesis of CdIn 2 S 4 . The In 2 O 3 –C/CdIn 2 S 4 heterojunction performed outstanding photocatalytic activity toward CO 2 reduction . Han et al fabricated a N-doped C-encapsulated In 2 O 3 –In 2 S 3 hollow dodecahedral heterostructure by sulfurization followed by carbonization of In-MOF and investigated their photocatalytic activity toward production of value-added chemicals .…”