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Constructing isotype g‐C3N4/g‐C3N4 heterojunction is an approach to improve the efficiency of g‐C3N4 towards solar‐assisted oxidation of water. Such functional configuration can effectively overcome the intrinsic drawback of rapid charge recombination of g‐C3N4. Here, a modified g‐C3N4, with homogeneous phosphorus doping, is prepared in this work through a phosphide‐involved gas phase reaction. The resulting P‐g‐C3N4 displays altered electronic structure, including upshifted band edge potential, narrowed band gap and improved electronic conductivity. These features allow P‐g‐C3N4 as an outstanding candidate to form isotype junction with pristine g‐C3N4. As expected, the accelerated charge separation and migration in target junction is validated by various measurements. The optimized isotype g‐C3N4/P‐g‐C3N4 heterojunction achieves a photocurrent as high as 0.3 mA cm−2 at 1.23 V vs RHE (AM 1.5G, 100 mW cm−2), representing 8‐fold's enhancement compared with pristine g‐C3N4. The present strategy for constructing g‐C3N4‐based isotype heterojunction networks is found effective for large‐scale manufacturing. Isotype photoanode: A phosphorus‐doped g‐C3N4 with suitable electronic structure was explored to construct metal‐free isotype photojunction in large‐scale manufacturing. The percolated networks exhibit largely increased photocurrent than its single component as a result of efficient charge transfer being qualitatively identified. [ABSTRACT FROM AUTHOR]

• Multitude advances were found for V-rich Bi 2 S 3 nanowire than pristine Bi 2 S 3 photoelectrode. • V-rich Bi 2 S 3 nanowires achieve excellent photocurrent density for water splitting under visible light. • Deep insights on how the V-rich feature affects the PEC performance of Bi 2 S 3. Bi 2 S 3 is a n-type (negative type) semiconductor that has a narrow band gap and an ideal band edge position for hydrogen generation. However, high charge recombination rate, low photoelectrochemical (PEC) efficiency and poor stability are of major concerns of Bi 2 S 3 as a photoelectrode. Herein, we report an efficient Vanadium-rich Bi 2 S 3 nanowires (atomic ratio of V to Bi is 1/22) that have been prepared on fluorine-doped tin oxide (FTO) substrate by an in-situ solution-processed reaction with BiVO 4 film as precursor. The resulting V-rich photoelectrode demonstrates notably high charge separation efficiency and fast charge transport with respect to pristine Bi 2 S 3 nanowires. As a result, the photocurrent density of ca. 10 mA·cm−2 at -0.2 V vs Ag/AgCl is obtained under visible light illumination. In addition, V-rich Bi 2 S 3 generates IPCE (incident photocurrent-to-current conversion efficiency) of 50% at 460 nm and 45% at 760 nm, demonstrating a 2.0 and 2.8-fold increase, respectively, when compared with pristine Bi 2 S 3. This enhancement is probably due to increased light absorption, less charge recombination, and faster charge transfer. More importantly, in contrast to pristine Bi 2 S 3 sample that suffers detrimental photocorrosion in sulfide containing electrolyte, V-rich Bi 2 S 3 nanowires retain 84.6% of its initial photocurrent over the course of 1 h. These findings are expected to shed light on engineering high-performance and robust metal sulfide materials for photoelectrochemical application. [ABSTRACT FROM AUTHOR]