Carbon nanotube-porphyrin photocatalysts

An assembly comprising a carbon nanotube coated successively with:

• a primary coating resulting from the polymerisation of an amphiphilic diynic compound of following formula (I):
• wherein:
• n is an integer from 6 to 20,
• m is an integer from 4 to 20,
• X1 is a covalent bond or a spacer unit, and
• R1 is an anionic group selected from COO−, SO3−, OSO3−, N((CH2)q1COO−)((CH2)q2COO−), N((CH2)q1SO3−)((CH2)q2SO3−), N((CH2)q1OSO3−)((CH2)q2OSO3−), CH((CH2)q3-1COO−)N((CH2)q1COO−)((CH2)q2COO−), CH((CH2)q3-1SO3−)N((CH2)q1SO3−)((CH2)q2SO3−) and CH((CH2)q3-1OSO3−)N((CH2)q1OSO3−)((CH2)q2OSO3−) with q1, q2 and q3, identical or different, each representing 1, 2, 3, 4, 5 or 6;
• or a cationic group selected from N+Alk1Alk2Alk3,
• wherein Alk1, Alk2 and Alk3 are independently a (C1-C6)alkyl;
• and
• a final coating of a porphyrin derivative which is either an anionic porphyrin or a cationic porphyrin,
• wherein the anionic porphyrin is an anionic tetraphenylporphyrin of following formula (IIa) or an anionic protoporphyrin of following formula (IIb):
• wherein:
• M is absent or is a metal selected from Zn, Mn, Fe, Cu, Co and Ni, and
• R2, R3, R4, and R5, identical or different, are selected from H, X2COO−, X2SO3−, and X2OSO3−, wherein X2 is a covalent bond or a spacer unit, and wherein at least one of R2, R3, R4, and R5 is not H,
• wherein the cationic porphyrin is a cationic tetraphenylporphyrin of following formula (IIc) or a cationic porphyrin of following formula (IId):
• wherein:
• M is as defined above,
• R6, R7, R8, and R9, identical or different, are selected from H, X3N+Alk4Alk5Alk6,
• wherein X3 is a covalent bond or a spacer unit, wherein Alk4, Alk5 and Alk6 are independently a (C1-C6)alkyl, and wherein at least one of R6, R7, R8, and R9 is not H, and
• R10, R11, R12, and R13, identical or different, are selected from H, X3N+Alk4Alk5Alk6,
• wherein X3, Alk4, Alk5 and Alk6 are as defined above, and wherein at least one of R10, R11, R12, and R13 is not H,
• wherein the porphyrin derivative is:
• a cationic porphyrin when R1 is an anionic group and there is no intermediate coating or when R1 is a cationic group and there is an intermediate coating of an anionic polymer, and
• an anionic porphyrin when R1 is a cationic group and there is no intermediate coating or when R1 is an anionic group and there is an intermediate coating of a cationic polymer.