What is the crystal structure of bismuth oxyhydroxyphosphate (BOHP)?

Question

The recent Chemical & Engineering News article Photocatalyst shreds drinking water contaminant PFOA report the following:

Cates and his colleagues made an accidental breakthrough while testing the photocatalyst bismuth phosphate. After finding that it could break down PFOA as effectively as a previously reported photocatalyst, gallium oxide, they tried to improve its performance by varying the pH of the reaction used to make the catalyst particles. The researchers had hoped this would change the particles’ size and shape, but the process inadvertently produced bismuth oxyhydroxyphosphate (BOHP). This new catalyst has the highest photocatalytic activity for PFOA degradation ever reported.

In lab tests under UV light, BOHP degraded all the PFOA in a 130 μM solution in about an hour, roughly 15 times faster than did bismuth phosphate or gallium oxide. BOHP performed almost as well over five repetitions of the experiment, suggesting it can be reused. To simulate PFOA-contaminated groundwater, the researchers then tested a more dilute solution of 1.2 μM PFOA accompanied by 500 μg dissolved organic carbon/L. In this case, the photocatalyst also degraded all the PFOA, though it took two hours. Strathmann calls it a “promising development” that advances the application of photocatalytic treatment of PFOA.

It also includes this SEM image of microcrystals of the "inadvertently produced bismuth oxyhydroxyphosphate (BOHP)."

The accidentally synthesized BOHP (shown) can break down the toxic industrial contaminant PFOA faster than any other photocatalyst. Credit: Environ. Sci. Technol. Lett.

A quick check with google doesn't send me to the materials Wikipedia page, and I'm wondering if that is because this is an unusual substance or the crystal structure hasn't been solved yet.

Question: What is the crystal structure of bismuth oxyhydroxyphosphate (BOHP)?

Answer 1

What is the crystal structure of bismuth oxyhydroxyphosphate (BOHP)?

Not exactly sure what an answer looks like so here is everything.

First off looking at the diffraction pattern from the paper, bismuth oxyhydroxyphosphate matches that of petitjeanite so that is definately the prototype structure.

Using the information about diffraction, from the ICDD Databse (pdf 01-082-8058)we find that petitjeanite is a triclinic system of the $\mathrm P\bar 1$ space group (#2). with lattice parameters of:

$\require{mediawiki-texvc}$ $$a = 9.798\AA; ~ b = 7.250\AA; ~ c= 6.866 \AA; \qquad \alpha = 88.280^\circ \beta = 115.270^\circ ~ \gamma = 110.700^\circ$$

and atomic positions of: $$\begin{array}{c|lll} \text{Atom}&x&y&z\\ \hline \ce{Bi}&~~~0.52327&~~~0.41421&~~~0.7523\\ \ce{Bi}&~~~0.29838&~~~0.74044&~~~0.55549\\ \ce{Bi}&~~~0.07735&~~~0.1609&~~~0.28045\\ \ce{P}&~~~0.6952&~~~0.0172&~~~0.9215\\ \ce{P}&~~~0.0961&~~~0.372&~~~0.7862\\ \ce{O}&~~~0.3777&~~~0.5382&~~~0.4759\\ \ce{O}&~~~0.3066&~~~0.1549&~~~0.5579\\ \ce{O}&~~~0.859&~~~0.0275&~~~0.8943\\ \ce{O}&~~~0.5569&-0.2084&~~~0.8602\\ \ce{O}&~~~0.621&~~~0.1596&~~~0.7526\\ \ce{O}&~~~0.7684&~~~0.1052&~~~1.1811\\ \ce{O}&~~~0.2584&~~~0.5101&~~~0.7497\\ \ce{O}&-0.0468&~~~0.4637&~~~0.6902\\ \ce{O}&~~~0.0209&~~~0.1498&~~~0.6362\\ \ce{O}&~~~0.1695&~~~0.3727&~~~1.0506\\ \end{array} $$

and last but not least this renders to an image of:

Purple: Bi
Orange: P
Red: O