Expediting H ₂ Evolution over MAPbI ₃ with a Nonnoble Metal Cocatalyst Mo ₂ C under Visible Light

Abstract

Halide perovskites have been emerging as promising photocatalytic materials for H2 evolution from water due to their outstanding photoelectric properties. However, the lack of proper surface reactive sites greatly hinders the photocatalytic potential of these fascinating compounds. Here, Mo2C nanoparticles have been anchored onto methylammonium lead iodide (MAPbI3) as a nonnoble metal cocatalyst to promote H2 evolution reactions. The Mo2C nanoparticles have opposite zeta potential with MAPbI3 thereby electrostatically assembled onto the MAPbI3 surface, i.e., Mo2C@MAPbI3. Our results show that the anchored Mo2C nanoparticles have a strong interplay with MAPbI3 substrate so that photogenerated electrons of MAPbI3 can be rapidly separated and transferred into Mo2C for further H2 evolution reactions. Under optimal conditions, Mo2C@MAPbI3 delivers exceptionally high photocatalytic performance for visible light-driven H2 evolution that clearly outperforms pristine MAPbI3 and Pt-deposited MAPbI3. An apparent quantum efficiency as high as 12.65% at 600±40 nm has been attained for H2 evolution, surpassing most of the MAPbI3-based photocatalyst reported. These results signify the usefulness and applicability of Mo2C as a new nonnoble metal-based cocatalyst in solar water splitting.

Hollow MoS2-supported MAPbI3composites for effective photocatalytic hydrogen evolution

“…It presents a volcano-type variation tendency for the H 2 evolution rates vs. H-MoS 2 content in the H-MoS 2 /MAPbI 3 composites. 42,43 The excess H-MoS 2 loading resulted in a decline of HER activity, probably ascribed to the aggregation of H-MoS 2 and/or the sheltering effect of MAPbI 3 . To be specific, the excess H-MoS 2 covered the surface of MAPbI 3 and then decreased the active surface sites and/or hampered the light absorption of MAPbI 3 .…”

Sizing Up Metal Halide Perovskite Photocatalysts: From Nano to Bulk

“…[88] Smaller surface-to-volume ratios presents a trade-off between fewer reaction sites and less vulnerability to surface environment conditions, but the use of cocatalysts can help to improve the area of active surface sites. [8]…”

“…In many cases, perovskite/cocatalyst composites have been formed in a similar fashion to what is presented in Figure 6a-c, and can often be synthesized through a direct mixing method wherein electrostatic attraction results in cocatalyst adhesion. [8,91,92] A wide variety of cocatalyst compositions have been utilized, including quantum-confined semiconductors of varying sizes, [92] as well as a variety of different morphologies of Mo-based semiconductors. [8,93,94] Reports of perovskite photocatalysts for HI splitting have predominately consisted of bulk perovskites rather than PNCs, which are more ubiquitous for all other applications.…”

“…Pairing photocatalysts with a cocatalyst material can improve charge separation, increase effective DOI: 10.1002/adom.202300626 surface area, and reduce the overpotential of the photocatalytic reaction (Figure 1b). [8][9][10] Adjustments to the energetic alignment for both the catalyst and cocatalyst facilitates charge separations where hole or electron extraction occurs (Figure 1c). Titanium dioxide (TiO 2 ), graphitic carbon nitride (g-C 3 N 4 ), bismuth vanadate (BiVO 4 ), and metal-organic frameworks (MOFs) represent some of the commonly studied conventional semiconductor photocatalysts; however, these materials often lack the prerequisite electronic tunability, long charge carrier lifetimes, and bandgaps within the range of visible light.…”

Chiral Inorganic Nanomaterials for Photo(electro)catalytic Conversion

“…Photo­(electro)­catalytic conversion, e.g., water splitting, CO 2 reduction, and N 2 fixation, have been focused in the field of inorganic catalysis for decades. − Intriguingly, the recent induction of chirality within inorganic NMs has emerged as a perspective and an avenue to regulate these catalytic processes. Chiral inorganic NMs as catalysts offer several advantages, such as vectorial recognition of light, electron spin regulation, and asymmetrical nanostructure, which can inspire versatile tactics to improve catalytic performance or even enable unanticipated catalytic reactions.…”