Z-scheme photocatalyst based on porphyrin derivative decorated few-layer BiVO4 nanosheets for efficient visible-light-driven overall water splitting

Abstract

It is highly desirable to simulate natural photosynthesis by using sunlight to drive the overall water splitting without using external bias and sacrificial agent. Herein, few-layer monoclinic BiVO 4 nanosheets (BVNS) with a thickness of ~4.3 nm, exposed (010) facets and abundant oxygen vacancies are fabricated using graphene oxide dots as templating reagent. After decorating with asymmetric chromium porphyrin derivative bearing one benzoic acid and three phenyls as meso-position substituents (chromium-5-(4-carboxyphenyl)-10,15,20-triphenylporphrin, CrmTPP) and PtO x cocatalyst, the obtained two-dimensional (2D) hybrid nanocomposite (BVNS/CrmTPP/Pt) with an optimal component ratio delivers a robust overall water splitting performance with a relatively high apparent quantum yield (8.67%) at 400 nm monochromatic light. The ultrathin structure and widely distributed oxygen vacancies on the exposed (010) facets of BVNS not only endow strong and intimate contact with the decorated CrmTPP molecules to promote a two-step excitation Z-scheme charge transfer mechanism for preserving the high redox ability of the photogenerated charge carriers, but also alleviate their recombination, and thus causing the robust overall water splitting performance of the 2D hybrid nanocomposites. The present results provide a novel strategy to construct highly efficient artificial photosynthetic system for overall water splitting.

Interface Engineering of a 2D/2D BiVO4/Bi4V2O10 Heterostructure with Improved Photocatalytic Photoredox Activity

“…To better overcome the shortcomings of bare BiVO 4 , construction of a BiVO 4 -based heterostructure by employing appropriate semiconductors is an effective manner to accelerate the charge carriers transfer and inhibit the recombination efficiency of photoexcited electron–hole pairs for photocatalytic performance boosting. − Recently, Bi 4 V 2 O 10 with a certain reduction ability has been investigated as a promising inexpensive and environmental-friendly semiconductor photocatalyst. Li has synthesized BiVO 4 /Bi 4 V 2 O 10 porous heterophase nanospheres with nanosized interfacial contact, which showed excellent photodegradation ability .…”

In situ growth of Ag2S quantum dots on SnS2 nanosheets with enhanced charge separation efficiency and CO2 reduction performance

“…Such excellent photochemical behavior of SnS 2 -200 indicates that the ultrathin SnS 2 -200 NSs formed by hydrothermal self-exfoliation can shorten the charge carrier migration distance inside SnS 2 -200 NSs to their surface. 29,59 After loading Ag 2 S QDs, SnS 2 /Ag 2 S-50 showed improved charge separation efficiency compared with pristine SnS 2 -200 (Fig. 8), which can be attributed to the effective electron separation between SnS 2 and Ag 2 S-50, retaining an intimate contact interface.…”

Efficient CO2 reduction over a Ru-pincer complex/TiO2 hybrid photocatalyst via direct Z-scheme mechanism

“…For comparison, Ru(N 3 )(ONO)/TiO 2 –Pt was also prepared through a similar procedure using 1.0 wt% Pt-loaded TiO 2 (TiO 2 –Pt), which was synthesized via a photodeposition method. 10…”

“…, metal oxides, 2,4,5 metal sulfides, 3,6 and some other non-metal materials 5,7 ) have been developed as photocatalysts for CO 2 RR, the corresponding photoreaction systems containing single-component photocatalyst are facing certain huge obstacles, such as low productivity, variable products, severe thermodynamic conditions, and difficulty in meeting the energy band structure requirements for CO 2 RR and water oxidation at the same time in a reaction system. 2,5 To solve these problems, various strategies including constructing multi-component composites (such as heterojunctions and Z-scheme systems 7–11 ), modifying the surface chemistry, and extending the spectral response region (such as cocatalyst loading and dye sensitization 4,5,9,12 ) have been explored. Among them, the construction of artificial Z-scheme systems mimicking natural photosynthesis is an effective and facile strategy, whereby the photosystem (PS) I and PS II of natural photosynthetic systems are replaced by two semiconductors that can be excited simultaneously, and the photoinduced electron transfer path follows the letter “Z” shape, similar to the natural photosynthesis, which can not only promote the charge separation but also maintain the high reduction ability of PSI and the high oxidation capacity of PS II.…”

“…Among them, the construction of artificial Z-scheme systems mimicking natural photosynthesis is an effective and facile strategy, whereby the photosystem (PS) I and PS II of natural photosynthetic systems are replaced by two semiconductors that can be excited simultaneously, and the photoinduced electron transfer path follows the letter “Z” shape, similar to the natural photosynthesis, which can not only promote the charge separation but also maintain the high reduction ability of PSI and the high oxidation capacity of PS II. 8–11…”