A Z‐Scheme Strategy that Utilizes ZnIn₂S₄ and Hierarchical VS₂ Microflowers with Improved Charge‐Carrier Dynamics for Superior Photoelectrochemical Water Oxidation

Abstract

One of the major limiting factorsf or efficient photoelectrochemical water oxidation is the fast recombination kinetics of photogenerated charge carriers. Herein,w ep ropose am odel system that utilizes ZnIn 2 S 4 and hierarchical VS 2 microflowersf or efficient charge separation through aZscheme pathway,w ithoutt he need for an electron mediator. An impressive 18-fold increase in photocurrent was observed for ZnIn 2 S 4 -VS 2 compared to ZnIn 2 S 4 alone. The charge-transfer dynamics in the composite were found to follow aZ -scheme pathway,w hich resulted in decreased charger ecombination and greater accumulation of the surface charge. Furthermore, slow kinetics of the surfacer eaction in the ZnIn 2 S 4 -VS 2 composite correlated to an increased surface-charge capacitance. This feature of the composite materialf acilitated partial storage of the photogenerated chargec arriers (e À /h + + )u nder illumination andd ark-current conditions, thus storing and utilizing solar energy more efficiently.

ZnIn2S4‐Based Photocatalysts for Energy and Environmental Applications

“…photocatalytic H 2 production, [145,146] 3D WS 2 /ZnIn 2 S 4 flower like microspheres for photocatalytic H 2 production [147] and Cr (VI) reduction, [148] 3D SnS/ZnIn 2 S 4 flowerlike microspheres for photocatalytic H 2 production, [149] 3D SnS 2 /ZnIn 2 S 4 flower like microspheres for photocatalytic Cr(VI) reduction, [150] bulk In 2 S 3 /ZnIn 2 S 4 for photocatalytic H 2 production, [151] NiS/ZnIn 2 S 4 porous nanosheets for photocatalytic H 2 production, [152] 3D PtS/ ZnIn 2 S 4 flowerlike microspheres for photocatalytic splitting of thiols to produce disulfides and H 2 , [153] 3D VS 2 /ZnIn 2 S 4 flower like microspheres for photoelectrochemical water oxidation, [154] Cu 7 S 4 /ZnIn 2 S 4 for photocatalytic H 2 production, [155] 3D CuS/ ZnIn 2 S 4 and Ag 2 S/ZnIn 2 S 4 flowerlike microspheres for H 2 pro duction and dye degradation, [156] Ir 2 S 3 /ZnIn 2 S 4 for photocata lytic H 2 production, [157] ReS 2 /ZnIn 2 S 4 for photocatalytic water splitting, [158] AgIn 5 S 8 /ZnIn 2 S 4 for photocatalytic H 2 produc tion [159] and dye degradation, [160] CdIn 2 S 4 /ZnIn 2 S 4 flowerlike microspheres for photocatalytic dye degradation [161] and H 2 evo lution, [162] and Fe 4 Ni 5 S 8 /ZnIn 2 S 4 flowerlike microspheres for photocatalytic coproduction of H 2 and organic chemicals. [163]…”

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

“…37,38 The pure ZIS exhibits a series of Raman bands at 243, 342, and 368 cm −1 , which correspond to longitudinal optical modes (OL1 and OL2) and A 1g mode of vibrations, whereas the band at 123 cm −1 confirms the layer hexagonal structure (Figure S3). 39 Similarly, the MIS with fd3m space group shows five Raman bands, which correspond to A 1g , E g , and 3F 2g modes (Figure S3). 40 The cubic CIS material exhibits characteristic Raman bands at 68, 124, and 288 cm −1 (Figure S3).…”

Emerging Layered Metallic Vanadium Disulfide for Rechargeable Metal‐Ion Batteries: Progress and Opportunities

“…In 2011, an ammonia-assisted strategy based on hydrothermal synthesis was successfully employed in the preparation of ultrathin VS 2 NSs (Figure 2), [43] which led the way to the actual hydrothermals ynthesis of nanostructured VS 2 . [60,84] In later studies, flowerlike, leaflike, and layer-by-layer-like VS 2 NSs with differentt hicknesses, as well as VS 2 quantum dots (Figure 3), were directly synthesized through ah ydrothermal method with Na 3 VO 4 •12 H 2 O/Na 3 VO 4 [43,48,49,52,54,60,62,70,71,82,[84][85][86][87][88][89][90][91] or NH 4 VO 3 [37,40,42,58,59,73,76,86,[92][93][94][95][96][97][98][99] as the Vs ource and thioacetamide (TAA) or N-acetyl-l-cysteine as the Ss ource (reductant). Meanwhile,V S 2 /graphene, [42,100] Na 2 Ti 2 O 5 /VS 2 , [101] VS 2 /carbon paper, [51] TiO 2 -B@VS 2 , [102] rGO/VS 2 [44,…”

“…In 2011, an ammonia‐assisted strategy based on hydrothermal synthesis was successfully employed in the preparation of ultrathin VS 2 NSs (Figure ), which led the way to the actual hydrothermal synthesis of nanostructured VS 2 . In later studies, flowerlike, leaflike, and layer‐by‐layer‐like VS 2 NSs with different thicknesses, as well as VS 2 quantum dots (Figure ), were directly synthesized through a hydrothermal method with Na 3 VO 4 ⋅ 12 H 2 O/Na 3 VO 4 or NH 4 VO 3 as the V source and thioacetamide (TAA) or N ‐acetyl‐ l ‐cysteine as the S source (reductant). Meanwhile, VS 2 /graphene, Na 2 Ti 2 O 5 /VS 2 , VS 2 /carbon paper, TiO 2 ‐B@VS 2 , rGO/VS 2 (Figure ), VOOH/VS 2 , VS 2 /MWCNTs, GNS/VS 2 , VS 2 ‐decorated graphitic carbon nitride (g‐C 3 N 4 ), VS 2 /CNT, Ni 3 S 2 /VS 2 , VS 2 /SS (Figure ), and NiCo 2 S 4 @VS 2 nanocomposites were also prepared through pure, cetyltrimethylammonium bromide (CTAB)‐assisted, or NaOH‐assisted hydrothermal reaction.…”

“…These characteristics endow VS 2 with abundant metal-ion storage sites (high theoreticalc apacity) and al ow ion diffusion barrier( fast reaction kinetics). [34,35] Apart from practical applications in LIBs, [36] SIBs, [37] KIBs, [38] MIBs, [39] ZIBs, [40] CIBs, [41] AIBs, [42] supercapacitors (SCs), [43] lithium-sulfur/selenium batteries (LiÀ S/Se), [44,45] and solid-state SC/lithium batteries, [46,47] VS 2 has also been used in aw ide variety of applications, such as electrocatalytic hydrogen evolution, [48][49][50][51] photoelectrochemicalw ater oxidation, [52] solar-drivenh ydrogen evolution, [53] solar cells, [54] magnetism/ferromagnetism, [55,56] spintronics, [57] humidity sensors and electrochemical biosensors, [58][59][60] touchless positioning interfaces, [61] field emitters, [62] cancert heranostics, [63] and cytotoxicity. [64] Nevertheless, only af ew specialized reviewsr elated to VS 2 have been reported in the literature (especially in the energy-storage field) and these mainly focus on the general progresso fm etal dichalcogenides.…”