Tungsten Disulfide‐Interfacing Nickel‐Porphyrin For Photo‐Enhanced Electrocatalytic Water Oxidation

Abstract

Covalent functionalization of tungsten disulfide (WS2) with photo‐ and electro‐active nickel‐porphyrin (NiP) is reported. Exfoliated WS2 interfacing NiP moieties with 1,2‐dithiolane linkages is assayed in the oxygen evolution reaction under both dark and illuminated conditions. The hybrid material presented, WS2−NiP, is fully characterized with complementary spectroscopic, microscopic, and thermal techniques. Standard yet advanced electrochemical techniques, such as linear sweep voltammetry, electrochemical impedance spectroscopy, and calculation of the electrochemically active surface area, are used to delineate the catalytic profile of WS2−NiP. In‐depth study of thin films with transient photocurrent and photovoltage response assays uncovers photo‐enhanced electrocatalytic behavior. The observed photo‐enhanced electrocatalytic activity of WS2−NiP is attributed to the presence of Ni centers coordinated and stabilized by the N4 motifs of tetrapyrrole rings at the tethered porphyrin derivative chains, which work as photoreceptors. This pioneering work opens wide routes for water oxidation, further contributing to the development of non‐noble metal electrocatalysts.

Field-effect transistor antigen/antibody-TMDs sensors for the detection of COVID-19 samples

“…More importantly, the intensities of 2LA(M) of MoS 2 bands decrease after functionalization, which is associated with covalent functionalization. [21][22][23][24][25][28][29][30][31][32][33] Further, XPS suggests reducing the number of sulphur defects, in agreement with Raman. 28,30 Finally, we could not detach the antibodies from MoS 2 without breaking the devices.…”

“…Basically, the thiols in our antibodies (calculate as 3% of cysteines in weight by Ellman's reagent vs. 1% in antigens) 34,37 react with bare metals at sulphur vacancies of MoS 2 and WS 2 . [21][22][23][24][25][26][27][28][29][30][31][32][33] Maldi-fingerprint before and after the reaction are identical, showing that antibodies do not degrade after the reaction (see ESI Fig. S2a †).…”

“…We have employed this strategy on phthalocyanine, 23 porphyrins, 24 polymers, 25 quantum dots 26,27 pyrenes, 28 or perylenes. 29 In addition, we previously proved that pyrene 30,31 and Ni-phorphyrin 32 induces electron transfer, leading to gating on FET devices to modify the carrier density of MoS 2 and WS 2 . Thus, a simple procedure should be developed to covalently functionalize TMDs with the cysteine (or cystine) of antibodies.…”

Localized Excitons in Zn-Porphyrin Covalently Functionalized MoS2 and WS2

“…We find sizeable binding energy (5.19 eV/ZnP) to the surface, suggesting axial organometallic-bounding between zinc in ZnP and sulfur on TMDs. Thus, while the covalent linker will prohibit the surface mobility of ZnP, the binding between ZnP and WS 2 is intrinsic and does not require the linker. , …”

“…Addition of zinc was carried out by a modified methodology described in the bibliography. , Free-porphyrin 2b was dissolved in 10 mL DCM. Drop a solution of ZnO­(Ac) 2 ·H 2 O (10 equiv) of 10 mL of MeOH under stirring.…”